Huatli, the Sun's Heart

Each creature you control assigns combat damage equal to its toughness rather than its power.
−3: You gain life equal to the greatest toughness among creatures you control.

Call to the Kindred

Enchant creature
At the beginning of your upkeep, you may look at the top five cards of your library. If you do, you may put a creature card that shares a creature type with enchanted creature from among them onto the battlefield, then you put the rest of those cards on the bottom of your library in any order.

Charix, the Raging Isle

Spells your opponents cast that target Charix cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Forest

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Island

Unsummon

Return target creature to its owner's hand.

Primal Rage

Creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Ancient Crab

Treefolk Umbra

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Counterspell

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Mana Leak

Counter target spell unless its controller pays {3}.

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Evolving Wilds

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

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.