Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Maelstrom Wanderer

Creatures you control have haste.
Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Then do it again.)

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Averna, the Chaos Bloom

As you cascade, you may put a land card from among the exiled cards onto the battlefield tapped. (Do this after the last card is exiled but before deciding whether to cast a nonland card.)

Gwenna, Eyes of Gaea

{T}: Add two mana in any combination of colors. Spend this mana only to cast creature spells or activate abilities of creature sources.
Whenever you cast a creature spell with power 5 or greater, put a +1/+1 counter on Gwenna, Eyes of Gaea and untap it.

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Thryx, the Sudden Storm

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Imoti, Celebrant of Bounty

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Old Gnawbone

Flying
Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

Cultivate

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Island

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.