msem-instigator

Flying
Whenever another creature you control dies, creatures you control get +1/+1 until end of turn.

Target creature gets +2/+2 and gains lifelink until end of turn. Whenever that creature perseveres this turn, target opponent loses 2 life. (A creature perseveres when it survives damage.)

Haste, prowess
Wanderlust — When Spitfireling enters, if you control four or more differently named lands, create two 1/1 red Elemental creature tokens with prowess and haste.

For each creature you control, put a +1/+1 counter on it or create a Treasure token.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Flying, haste
Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Splitflame Phoenix dies, you may pay {R}. If you do, return it to its owner's hand.

Vigilance, reach
{T}: Splitshaft Deadeye deals damage equal to its power to target creature with flying.

Lifelink
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Spoiled Oracle mentors a creature, that creature gains lifelink until end of turn.

When Spoiled Prince enters, each player sacrifices a creature with the greatest power among creatures they control.

At the beginning of your upkeep, each opponent mills two cards.
{3}{B}: Exile target nonland card from an opponent's graveyard. Copy it. You may cast the copy. Activate only as a sorcery. (You still pay its costs, including color. Copies of permanents enter as tokens.)

Whenever a land you control enters, you may pay {1}. If you do, create a 1/1 green Saproling creature token.

Germinate three times. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

When Sporecrowned Scavenger enters, target opponent loses life equal to the number of Insects you control and you gain that much life.

Whenever Sporeflow Propagator or another nontoken creature you control enters, germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

As an additional cost to cast this spell, sacrifice a permanent.
Sporesowed Disease deals 3 damage to any target and you gain 3 life.

Cast this spell only if an opponent controls a creature with power 5 or greater or you control six or more lands.
Return all nonland permanents target player controls to their owner's hand.

Target creature gets -2/-2 until end of turn. When that creature dies this turn, create a tapped 2/2 black Zombie creature token.

When Spreading Dissent enters, exile all creatures until Spreading Dissent leaves the battlefield.
{X}: Put a random creature card with mana value X exiled with Spreading Dissent onto the battlefield. Any player may activate this ability.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Sacrifice any number of lands. Search your library for that many basic land cards, put them onto the battlefield, then shuffle.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Another target creature you control gets +1/+1 until end of turn.
[Lore III] Search your library for a basic land card, put it onto the battlefield, then shuffle.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on a creature you control, target creature gains trample until end of turn.

Whenever a creature you control enters, if you didn't cast it from your hand, put a +1/+1 counter on it.
{3}{W}: Exile target creature you control, then return it to the battlefield under its owner's control.

Defender
Prismatic — Whenever you cast a multicolored spell, Squall Serpent gets +1/+1 until end of turn and can attack this turn as though it didn't have defender.