Vigilance, reach
When Thundering Serpent enters, you gain 6 life.

When Towering Sentinel enters, for each kind of counter among permanents you control, put a counter of that kind on Towering Sentinel, then add {G} or {U}.

Approval — When Triumphant Herd enters, you gain X life, where X is the number of colors among permanents you control.

When Vishanki Ambassador enters, each opponent loses 3 life and you gain 3 life.
Basic landcycling {1}{R}

As long as you control four or more lands with different names, Worldtreader Beast can't be blocked by creatures with power 2 or less.

Flash
{2}{B}, Discard Zyxthax Apex: Each opponent loses 3 life and you gain 3 life.
{6}{B}{B}: Return Zyxthax Apex from your graveyard to the battlefield tapped with a finality counter on it.

Menace
Drop — Whenever Avatar of the Decks or another creature you control enters, if the entering creature was cast, sacrifice a permanent unless you didn't cast any creature spells during your last turn.

Haste
Drop — Whenever Avatar of the Moshpit or another creature you control enters, if the entering creature was cast and you didn't cast any creature spells during your last turn, discard your hand, then draw three cards.

Reach
Drop — Whenever Avatar of the Rave or another creature you control enters, if the entering creature was cast and you didn't cast any creature spells during your last turn, return up to two target cards from your graveyard to your hand.

Menace
Bastion Breaker can't block.

Flash
Ward {3}
You may reveal the second card you draw each turn as you draw it. When you do, you may cast it without paying its mana cost. If you didn't cast a spell this way, create two Treasure tokens.

All spells cost {1} more to cast.
Spellcharge 6

Flash
Approval — When Congressional Kraken enters, return each nonland permanent with mana value less than or equal to the number of colors among permanents you control to their owners' hands.

Flash
When Corrosive Spitter enters, destroy all creatures that were dealt damage this turn.

When D'Enzo Orsino enters, you may search your library for a card named Marie Laurent, a card named Hans Nehmann and a card named Diago Maldovo, reveal them, put them into your hand, then shuffle.
Prevent all combat damage that would be dealt to legendary Allies you control.

Hexproof
When Dakran Shipcrusher enters, you may bless target creature.

Deathtouch
{2}, Discard Darkhunt Pesanta: Search your library for a basic Swamp card, reveal it, put it into your hand, then shuffle.

If you have more life than your starting life total, this spell costs {X} less to cast, where X is equal to the difference.
Trample
When Glacier Guardian enters, you may have it fight target creature you don't control.

At the beginning of your end step, if you cast no spells this turn, surveil 1.
Spellcharge 6

This spell can't be countered.
Flying, ward {2}
Whenever Hoarding Culebre enters or attacks, draw a card. Then if you have five or more cards in hand, create a Treasure token.

Trample
When Hunger's Door enters, you may return target Aura card from your graveyard to the battlefield attached to Hunger's Door.

Master of the Ring enters with an opponent's choice of two different counters on it from among menace, first strike, and trample.

Flying
Whenever Molten Slagmaw enters or attacks, each opponent sacrifices an artifact or nonbasic land.

Whenever Phlage enters or attacks, Phlage deals 2 damage to any target and you draw a card.
{2}{U}{R}: Return Phlage from your graveyard to the battlefield, then put it on the bottom of its owner's library. Activate only as a sorcery.

As an additional cost to cast spells during an opponent's turn, you may pay {U} and reveal Promethean Jaxl from your hand. If you do, you get a lurk counter.
Flash
Promethean Jaxl enters tapped.
When Promethean Jaxl enters, you draw a card for each lurk counter you have, then you lose all lurk counters.