Plan on cutting

Slice from the Shadows

This spell can't be countered. (This includes by the ward ability.)
Target creature gets -X/-X until end of turn.

Have

Blooming Marsh

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Underdark Rift

{T}: Add {C}.
{5}, {T}, Exile this land: Roll a d10. Put target artifact, creature, or planeswalker into its owner's library just beneath the top X cards of that library, where X is the result. Activate only as a sorcery.

Temple of Cultivation

(Transforms from Ojer Kaslem, Deepest Growth.)
{T}: Add {G}.
{2}{G}, {T}: Transform this land. Activate only if you control ten or more permanents and only as a sorcery.

Ojer Kaslem, Deepest Growth

Trample
Whenever Ojer Kaslem deals combat damage to a player, reveal that many cards from the top of your library. You may put a creature card and/or a land card from among them onto the battlefield. Put the rest on the bottom in a random order.
When Ojer Kaslem dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Kaslem, Deepest Growth // Temple of Cultivation

Grothama, All-Devouring

Other creatures have "Whenever this creature attacks, you may have it fight Grothama, All-Devouring."
When Grothama leaves the battlefield, each player draws cards equal to the amount of damage dealt to Grothama this turn by sources they controlled.

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

The Gitrog, Ravenous Ride

Trample, haste
Whenever The Gitrog deals combat damage to a player, you may sacrifice a creature that saddled it this turn. If you do, draw X cards, then put up to X land cards from your hand onto the battlefield tapped, where X is the sacrificed creature's power.
Saddle 1

Foul Orchard

This land enters tapped.
{T}: Add {B} or {G}.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Clackbridge Troll

Trample, haste
When this creature enters, target opponent creates three 0/1 white Goat creature tokens.
At the beginning of combat on your turn, any opponent may sacrifice a creature of their choice. If a player does, tap this creature, you gain 3 life, and you draw a card.

Pillage the Bog

Look at the top X cards of your library, where X is twice the number of lands you control. Put one of them into your hand and the rest on the bottom of your library in a random order.
Plot {1}{B}{G} (You may pay {1}{B}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Collective Resistance

Escalate {G} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target artifact.
• Destroy target enchantment.
• Target creature gains hexproof and indestructible until end of turn.

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Golgari Guildgate

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Terrian, World Tyrant

Terramorphic Expanse

Oakhollow Village

{T}: Add {C}.
{T}: Add {G}. Spend this mana only to cast a creature spell.
{G}, {T}: Put a +1/+1 counter on each Frog, Rabbit, Raccoon, or Squirrel you control that entered the battlefield this turn.

Kraul Whipcracker

Reach
When this creature enters, destroy target token an opponent controls.

Temple of Malady

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {G}.

Overlord of the Hauntwoods

Impending 4—{1}{G}{G} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, create a tapped colorless land token named Everywhere that is every basic land type.

Springheart Nantuko

Bestow {1}{G}
Enchanted creature gets +1/+1.
Landfall — Whenever a land you control enters, you may pay {1}{G} if this permanent is attached to a creature you control. If you do, create a token that's a copy of that creature. If you didn't create a token this way, create a 1/1 green Insect creature token.

Crash of Rhino Beetles

Trample
This creature gets +10/+10 as long as you control ten or more lands.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, create X X/X green Hydra creature tokens.

Primal Wellspring

(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Primal Amulet

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on this artifact. Then if there are four or more charge counters on it, you may remove those counters and transform it.

Primal Amulet // Primal Wellspring

Mudflat Village

{T}: Add {C}.
{T}: Add {B}. Spend this mana only to cast a creature spell.
{1}{B}, {T}, Sacrifice this land: Return target Bat, Lizard, Rat, or Squirrel card from your graveyard to your hand.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, create a 4/4 green Beast creature token.

Dark Depths

Dark Depths enters with ten ice counters on it.
{3}: Remove an ice counter from Dark Depths.
When Dark Depths has no ice counters on it, sacrifice it. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Elegy Acolyte

Lifelink
Whenever one or more creatures you control deal combat damage to a player, you draw a card and lose 1 life.
Void — At the beginning of your end step, if a nonland permanent left the battlefield this turn or a spell was warped this turn, create a 2/2 colorless Robot artifact creature token.

Possible additions

Abundance

If you would draw a card, you may instead choose land or nonland and reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and put all other cards revealed this way on the bottom of your library in any order.

Back for More

Return target creature card from your graveyard to the battlefield. When you do, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Mossborn Hydra

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature enters with a +1/+1 counter on it.
Landfall — Whenever a land you control enters, double the number of +1/+1 counters on this creature.

Forest

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Darkmoss Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {G}.

Shifting Woodland

This land enters tapped unless you control a Forest.
{T}: Add {G}.
Delirium — {2}{G}{G}: This land becomes a copy of target permanent card in your graveyard until end of turn. Activate only if there are four or more card types among cards in your graveyard.

Old-Growth Grove

Revitalizing Repast

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

Revitalizing Repast // Old-Growth Grove

Chorale of the Void

Enchant creature you control
Whenever enchanted creature attacks, put target creature card from defending player's graveyard onto the battlefield under your control tapped and attacking.
Void — At the beginning of your end step, sacrifice this Aura unless a nonland permanent left the battlefield this turn or a spell was warped this turn.

Tenacious Underdog

Blitz—{2}{B}{B}, Pay 2 life. (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)
You may cast this card from your graveyard using its blitz ability.

Shakedown Heavy

Menace
Whenever this creature attacks, defending player may have you draw a card. If they do, untap this creature and remove it from combat.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Arco-Flagellant

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
This creature can't block.
Endurant — Pay 3 life: This creature gains indestructible until end of turn.

Topiary Stomper

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
This creature can't attack or block unless you control seven or more lands.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Full Steam Ahead

Until end of turn, each creature you control gets +2/+2 and gains trample and "This creature can't be blocked by more than one creature."

Hunted Bonebrute

Menace
When this creature enters, target opponent creates two 1/1 white Dog creature tokens.
When this creature dies, each opponent loses 3 life.
Disguise {1}{B}

Yargle and Multani

Turntimber, Serpentine Wood

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {G}.

Turntimber Symbiosis

Look at the top seven cards of your library. You may put a creature card from among them onto the battlefield. If that card has mana value 3 or less, it enters with three additional +1/+1 counters on it. Put the rest on the bottom of your library in a random order.

Turntimber Symbiosis // Turntimber, Serpentine Wood

Eumidian Terrabotanist

Landfall — Whenever a land you control enters, you gain 1 life.

Riveteers Overlook

When this land enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Unbound Flourishing

Whenever you cast a permanent spell with a mana cost that contains {X}, double the value of X.
Whenever you cast an instant or sorcery spell or activate an ability, if that spell's mana cost or that ability's activation cost contains {X}, copy that spell or ability. You may choose new targets for the copy.

Badlands Revival

Return up to one target creature card from your graveyard to the battlefield. Return up to one target permanent card from your graveyard to your hand.

Quakestrider Ceratops

Leyline Surge

At the beginning of your upkeep, you may put a permanent card from your hand onto the battlefield.

Invasion of Shandalar

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, return up to three target permanent cards from your graveyard to your hand.

Invasion of Shandalar // Leyline Surge

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

Alpha Deathclaw

Menace, trample
When this creature enters or becomes monstrous, destroy target permanent.
{5}{B}{G}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)

Lumra, Bellow of the Woods

Vigilance, reach
Lumra's power and toughness are each equal to the number of lands you control.
When Lumra enters, mill four cards. Then return all land cards from your graveyard to the battlefield tapped.

Bleed Dry

Target creature gets -13/-13 until end of turn. If that creature would die this turn, exile it instead.

Bramble Wurm

Reach, trample
When this creature enters, you gain 5 life.
{2}{G}, Exile this card from your graveyard: You gain 5 life.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Don't Have

Verdant Outrider

{1}{G}: This creature can't be blocked by creatures with power 2 or less this turn.

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land you control enters, you gain 1 life.

Primeval Bounty

Whenever you cast a creature spell, create a 3/3 green Beast creature token.
Whenever you cast a noncreature spell, put three +1/+1 counters on target creature you control.
Landfall — Whenever a land you control enters, you gain 3 life.

Festering Gulch

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {B} or {G}.

Restart Sequence

Freerunning {1}{B} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Return target creature card from your graveyard to the battlefield.

Lively Dirge

Spree (Choose one or more additional costs.)
+ {1} — Search your library for a card, put it into your graveyard, then shuffle.
+ {2} — Return up to two creature cards with total mana value 4 or less from your graveyard to the battlefield.

Boseiju, Who Shelters All

Boseiju enters tapped.
{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

Nyxborn Hydra

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Reach, trample
This permanent enters with X +1/+1 counters on it.
Enchanted creature gets +1/+1 for each +1/+1 counter on this Aura and has reach and trample.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Skyclave Shade

Kicker {2}{B}
This creature can't block.
If this creature was kicked, it enters with two +1/+1 counters on it.
Landfall — Whenever a land you control enters, if this card is in your graveyard and it's your turn, you may cast it from your graveyard this turn.

Cultivator Colossus

Trample
Cultivator Colossus's power and toughness are each equal to the number of lands you control.
When this creature enters, you may put a land card from your hand onto the battlefield tapped. If you do, draw a card and repeat this process.

Agonasaur Rex

Trample
Cycling {2}{G} ({2}{G}, Discard this card: Draw a card.)
When you cycle this card, put two +1/+1 counters on up to one target creature or Vehicle. It gains trample and indestructible until end of turn.

Silence the Believers

Strive — This spell costs {2}{B} more to cast for each target beyond the first.
Exile any number of target creatures and all Auras attached to them.

Rot-Curse Rakshasa

Trample
Decayed (This creature can't block. When it attacks, sacrifice it at end of combat.)
Renew — {X}{B}{B}, Exile this card from your graveyard: Put a decayed counter on each of X target creatures. Activate only as a sorcery.

Territorial Scythecat

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature.

Iridescent Vinelasher

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Landfall — Whenever a land you control enters, this creature deals 1 damage to target opponent.

Intrepid Stablemaster

Reach
{T}: Add {G}.
{T}: Add two mana of any one color. Spend this mana only to cast Mount or Vehicle spells.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Vorpal Sword

Equipped creature gets +2/+0 and has deathtouch.
{5}{B}{B}{B}: Until end of turn, this Equipment gains "Whenever equipped creature deals combat damage to a player, that player loses the game."
Equip {B}{B}

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Pugnacious Hammerskull

Whenever this creature attacks while you don't control another Dinosaur, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Gloomshrieker

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, return target permanent card from your graveyard to your hand.
If this creature would die, exile it instead.

Dig Up

Cleave {1}{B}{B}{G} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Search your library for a [basic land] card, [reveal it,] put it into your hand, then shuffle.

Thought Vessel

Alpha Authority

Enchant creature
Enchanted creature has hexproof and can't be blocked by more than one creature.

Nature's Will

Whenever one or more creatures you control deal combat damage to a player, tap all lands that player controls and untap all lands you control.

Quest for the Necropolis

Landfall — Whenever a land you control enters, put a quest counter on this enchantment.
{5}{B}, Sacrifice this enchantment: Put target creature card from a graveyard onto the battlefield under your control. This ability costs {1} less to activate for each quest counter on this enchantment. Activate only as a sorcery.

Fell Mire

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.