msem-instigator

Whenever you gain life, target opponent loses that much life.

Up to three target creatures each get +1/+1 until end of turn.

Whenever one or more nontoken Merfolk you control attack, create a 2/1 red Merfolk creature token.

Indestructible
Whenever a creature an opponent controls dies, put five +1/+1 counters on Scion of Death.

{2}{W}, {T}: Target creature gets +2/+2 and gains first strike until end of turn.

Primal {3}{U}{U} (During your turn, you may cast this spell for {3}{U}{U} instead of playing a land.)
Draw a card for each land you control, then discard that many cards unless this spell was cast for its primal cost.

At the beginning of your upkeep, you gain 1 life. Then if your life total is greater than or equal to your starting life total, you gain an additional 1 life and scry 1. Then if your life total is greater than or equal to three times your starting life total, you win the game.

{T}: Add {R} or {W}.
{R}{W}, {T}: Target creature gains first strike and haste until end of turn.

Primal {W} (During your turn, you may cast this spell for {W} instead of playing a land.)
Destroy target attacking or blocking creature.

Deathtouch
Cards can't leave graveyards.
If a creature would die, you may pay {X}, where X is the number of cards in your graveyard. If you do, instead exile it, then return that card to the battlefield under your control.

Reveal the top five cards of your library. Put one of those cards into your hand. Target opponent chooses two of those cards. Exile the chosen cards, then put the rest into your hand.

{T}, Sacrifice Serene Trail: Search your library for a Forest or Plains card and put it onto the battlefield tapped, then shuffle.

Destroy target token.

Other creatures you control get +0/+1.
Whenever a creature you control perseveres, you gain 1 life. (A creature perseveres when it survives damage.)

Enchant creature
Enchanted creature has lifelink and protection from its colors. This effect doesn't remove Shimmerhold. (This permanent can't be targeted, dealt damage, enchanted, or equipped by anything its color.)

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
When Shoring Naiad enters, if {U} was spent to cast it, you may return an instant or sorcery card from your graveyard to your hand.

Enchant creature
Enchanted creature gets +1/+0 and has deathtouch.
When Sickening Madness is put into a graveyard from the battlefield, draw a card.

Target player draws two cards and loses 2 life.

When Silence Dissent enters, each player exiles a card from their hand at random until Silence Dissent leaves the battlefield.
{1}{W}: Exile Silence Dissent. Return it to the battlefield under your control at the beginning of your next end step.

Whenever you draw a card, Silverblood Aspirant gets +1/+1 until end of turn.
{1}{R}, Discard a card: Draw a card.

Creatures with power less than Skull-Crowned Chief's power can't block.

Slippery Capuchin can't be blocked.
Whenever Slippery Capuchin becomes the target of a spell or ability, you may change the target of that spell or ability.

Sneaking Capuchin can't be blocked except by creatures with defender.
{U}: Counter target spell or ability that targets Sneaking Capuchin.

Creatures with power less than Sneaking Peak's power can't block it.
At the beginning of your end step, if Sneaking Peak didn't attack this turn, put a +1/+1 counter on it.

First strike, haste
Whenever Soulflare Nymph deals damage to a creature, exile that creature.