msem-instigator

{R}{W}{B}, Discard a card named Ni'Ama, God of Adversity: Ni'Ama gains indestructible and becomes a God creature in addition to its other types.
Whenever Ni'Ama enters or attacks, it deals 2 damage to each opponent unless they discard a card. You gain that much life. Repeat this process once.

This spell costs {X} less to cast, where X is the greatest power among creatures you controlled that died this turn.
Flash
Flying, trample

Whenever a storied permanent you control enters, each opponent discards a card. (Enchantments and legendary permanents are storied.)

Indestructible
When this creature transforms into Ninhasir, God of Creation, discard all the cards in your hand, then draw that many cards plus one.
Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.

Trample
Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
When Nonpareil of the Abyss enters, create an Idol token.
Nonpareil of the Abyss has ward {8} as long as you're in a renaissance.

When Norwick Militia enters, other Citizens and Peasants you control get +1/+1 and gain vigilance until end of turn.

Flying
Whenever Novaheart Dragon enters or attacks, you may take an extra turn after this one. If you do, you lose the game at the beginning of that turn's end step.

Indestructible
As long as your devotion to green is less than five, Nylea isn't a creature.
Whenever another creature you control deals combat damage to a player, draw a card.
{1}{G}: Until end of turn, another target creature you control gains haste and can't be blocked by creatures with power 3 or less.

Deathtouch
When Nyx-Eater Basilisk enters, exile up to one target enchantment.
{2}{G}, Discard Nyx-Eater Basilisk: Exile target enchantment.

Trample
When Oakcudgel Giant enters, you may destroy target artifact or enchantment.

Whenever a creature you control dies, Oakpoint gets +4/+0 until end of turn.

Trample
Assault {1}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, draw a card.

Defender
As long as your fealty to Islands is six or greater, Oasis Glutton can attack as though it didn't have defender. (Each Island you control counts towards your fealty to Islands.)

Flash
Ocean's Edge Kraken enters with a hexproof counter on it.
{6}{U}{U}, Remove a hexproof counter from Ocean's Edge Kraken: Return all other creatures to their owners' hands.

When Ol' Sycamore enters, choose up to two —
• Ol' Sycamore fights another target legendary creature.
• Destroy target noncreature storied permanent. (Enchantments and legendary permanents are storied.)

Defender, flying
Menagerie — As long as there are five or more creature types among creatures you control, Old-Rune Sentinel can attack as though it didn't have defender.

Vigilance
When Olde King Koswe enters, reveal the top eight cards of your library. Put any number of permanent cards from among them onto the battlefield under an opponent's control, then put the rest on the bottom of your library in a random order.
At the beginning of your end step, gain control of target permanent you own.

Trample, haste
Whenever an opponent casts a noncreature spell, you may return Olten Sandwurm to its owner's hand.

Trample
Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Cycling {2} ({2}, Discard this card: Draw a card.)

Reach
When Oltenen Terror enters, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
{1}{G}, Sacrifice an artifact or creature: Tap Oltenen Terror. It gains indestructible until end of turn.

{3}{U}, Exile a card from your graveyard: Omen Serpent can't be blocked this turn.

Play with the top card of your library revealed.
Whenever you draw a card, destroy each creature with the same mana value as that card.

Flying
Whenever Omid enters or one or more Armies you control attack, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Spells your opponents cast that target Onigori, Ema's Shield cost {2} more to cast.
Whenever Onigori deals combat damage to a player, that player can't untap more than two permanents during their next untap step.

Flying
Creatures you don't control have “{T}: This creature fights Ontarachie Apex. Activate only as a sorcery.”