Pathbreaker Ibex

Whenever this creature attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Druids' Repository

Whenever a creature you control attacks, put a charge counter on this enchantment.
Remove a charge counter from this enchantment: Add one mana of any color.

The Skullspore Nexus

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures.
{2}, {T}: Double target creature's power until end of turn.

Swarmyard

{T}: Add {C}.
{T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

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}

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.

Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Exploration

You may play an additional land on each of your turns.

Forsaken Crossroads

Forsaken Crossroads enters the battlefield tapped.
As Forsaken Crossroads enters the battlefield, choose a color.
When Forsaken Crossroads enters the battlefield, scry 1. If you weren't the starting player, you may untap Forsaken Crossroads instead.
{T}: Add one mana of the chosen color.

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Concordant Crossroads

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.