Loran of the Third Path

Vigilance
When Loran enters, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Luxior, Giada's Gift

Equipped creature gets +1/+1 for each counter on it.
Equipped permanent isn't a planeswalker and is a creature in addition to its other types. (Loyalty abilities can still be activated.)
Equip planeswalker {1}
Equip {3}

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Savannah

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Choke

Islands don't untap during their controllers' untap steps.

Oppression

Whenever a player casts a spell, that player discards a card.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. This artifact deals 1 damage to you.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice this creature: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Command Tower

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, this creature gets +5/+5 and has flying.

Tayam, Luminous Enigma

Each other creature you control enters with an additional vigilance counter on it.
{3}, Remove three counters from among creatures you control: Mill three cards, then return a permanent card with mana value 3 or less from your graveyard to the battlefield.

Fiend Artisan

This creature gets +1/+1 for each creature card in your graveyard.
{X}{B/G}, {T}, Sacrifice another creature: Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Shield Mate

Sacrifice this creature: Target creature gets +0/+4 until end of turn.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on this creature.

Bayou

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Imperial Seal

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Culling Ritual

Destroy each nonland permanent with mana value 2 or less. Add {B} or {G} for each permanent destroyed this way.

City of Brass

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Scrubland

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on this creature: Untap this creature.

Mox Jet

Survival of the Fittest

{G}, Discard a creature card: Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Witherbloom Apprentice

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 1 life and you gain 1 life.