As long as it's your turn, commanders you control have indestructible. (Effects that say "destroy" don't destroy them. A creature with indestructible can't be destroyed by damage.)

Partner (You can have two commanders if both have partner.)

Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, tap up to X target creatures, where X is the number of times this creature has mutated. Those creatures don't untap during their controller's next untap step.

Mutate {5}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times this creature has mutated. Put those permanent cards onto the battlefield.

Hexproof, reach

Mutate {2}{B/G}{B/G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, return target permanent card from your graveyard to your hand.

Mutate {2}{U/B}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

You may cast Brokkos, Apex of Forever from your graveyard using its mutate ability.

Mutate {3}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Menace (This creature can't be blocked except by two or more creatures.)

Whenever this creature mutates, each opponent discards a card.

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, each opponent sacrifices a creature.

Return target nonland permanent you don't control to its owner's hand.

Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Flying

Lieutenant -- As long as you control your commander, Demon of Wailing Agonies gets +2/+2 and has "Whenever Demon of Wailing Agonies deals combat damage to a player, that player sacrifices a creature."

Mutate {4}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Flying

Whenever this creature mutates, destroy target creature or planeswalker an opponent controls.

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, draw a card.

Flying

Spells your opponents cast that target one or more commanders you control cost {3} more to cast.

Partner (You can have two commanders if both have partner.)

Commanders you control have menace and deathtouch.

Partner (You can have two commanders if both have partner.)

Mutate {1}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Reach, trample

Whenever this creature mutates, destroy target artifact or enchantment an opponent controls.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Reach

Whenever this creature mutates, put two +1/+1 counters on it.

Choose one --

• All creatures get -1/-1 until end of turn.

• Destroy target enchantment.

• Regenerate each creature you control.

Flash

Commander creatures you control get +2/+2.

Commanders you control have hexproof.

Mutate {2}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Deathtouch

Whenever this creature mutates, each opponent loses X life and you gain X life, where X is the number of times this creature has mutated.

This spell can't be countered.

At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.

Sacrifice another Serpent: Choose one --

• Tap target permanent. Its activated abilities can't be activated this turn.

• Koma, Cosmos Serpent gains indestructible until end of turn.

Flying

Lieutenant -- At the beginning of combat on your turn, if you control your commander, draw a card.

Trample

Lieutenant -- At the beginning of combat on your turn, if you control your commander, put a +1/+1 counter on each creature you control.

Menace

Lieutenant -- At the beginning of combat on your turn, if you control your commander, each opponent loses 3 life.

Mutate {2}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, exile the top card of each opponent's library face down. You may look at and play those cards for as long as they remain exiled.

Mutate {1}{B}{G}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature deals combat damage to a player, return target creature card with mutate from your graveyard to your hand.

Mutate {G}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

{1}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield. If you don't put the card onto the battlefield, put it into your hand.

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Whenever this creature mutates, you may return target creature an opponent controls to its owner's hand.

Indestructible

Whenever Predator Ooze attacks, put a +1/+1 counter on it.

Whenever a creature dealt damage by Predator Ooze this turn dies, put a +1/+1 counter on Predator Ooze.

Choose two --

• Return target creature or planeswalker to its owner's hand.

• Counter target artifact or enchantment spell.

• Put two +1/+1 counters on target creature.

• Target player shuffles up to three target cards from their graveyard into their library.

Indestructible

Whenever Sapling of Colfenor attacks, reveal the top card of your library. If it's a creature card, you gain life equal to that card's toughness, lose life equal to its power, then put it into your hand.

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature mutates, destroy target noncreature permanent. Its controller creates a 3/3 green Beast creature token.

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Whenever this creature deals combat damage to a player, draw a card.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Silhana Ledgewalker can't be blocked except by creatures with flying.

Choose two --

• Counter target noncreature spell.

• Return target permanent to its owner's hand.

• Target creature gets -3/-3 until end of turn.

• Destroy target planeswalker.

Choose one --

• Target creature gets +3/+3 until end of turn.

• Permanents you control gain hexproof until end of turn.

• Return target creature to its owner's hand.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, gain control of target noncreature artifact.

Hexproof

Lieutenant -- As long as you control your commander, Stormsurge Kraken gets +2/+2 and has "Whenever Stormsurge Kraken becomes blocked, you may draw two cards."

Choose one --

• Destroy target monocolored creature.

• Destroy target artifact or enchantment.

• Draw two cards, then discard a card.

Trample

Lieutenant -- As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

Tome of Legends enters the battlefield with a page counter on it.

Whenever your commander enters the battlefield or attacks, put a page counter on Tome of Legends.

{1}, {T}, Remove a page counter from Tome of Legends: Draw a card.

This spell can't be countered.

Indestructible

Toski, Bearer of Secrets attacks each combat if able.

Whenever a creature you control deals combat damage to a player, draw a card.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

{1}{G}: Regenerate Troll Ascetic.

Mutate {3}{G/U}{G/U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, create a 3/3 green Beast creature token.