msem-instigator

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

Menace, haste
Whenever another player casts a spell that targets Plasma Addict, that player gains control of Plasma Addict.

{1}{U}, {T}: Draw a card, then discard a card.

Whenever you draw your second card each turn, put a +1/+1 counter on Current Surfer.
{R}, Discard your hand, Sacrifice Current Surfer: Draw X cards, where X is its power. At the beginning of the next end step, discard your hand.

First strike
Whenever you cast an instant or sorcery spell, if Branch Breaker dealt combat damage to a player this turn, you may sacrifice Branch Breaker. If you do, copy that spell. You may choose new targets for the copy.

{1}{G/W}: Put a +1/+1 counter on Artful Chari.
Whenever you cast an instant or sorcery spell, you may remove a number of +1/+1 counters from Chari equal to that spell's mana value. If you do, copy that spell, and you may choose new targets for the copy.

When Fallspeaker Satyr enters or dies, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

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

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life unless that player is cursed.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
Spells you cast that share a type with the card Chillwhisper Witch engorged cost {1} less to cast.

Conjure Quicksand deals 1 damage to each creature and planeswalker you don't control and each battle you don't protect.

Brilliant Runepearl enters tapped.
Whenever you cast a permanent spell, you gain 1 life.
{T}: Add one mana of any color. Spend this mana only to cast permanent spells.

Destroy target artifact. Scry 1.

When you cast Senaturian Centurion, reveal cards from the top of your library until you reveal a creature card with mana value 2 or less. Copy that card, then put the revealed card into your hand. You may cast the copy without paying its mana cost. Put the revealed cards on the bottom of your library in a random order.

When Roving Chaplains enters, create two 1/1 white Spirit creature tokens with flying.
{W}, Tap another untapped creature you control: Tap target nonland permanent an opponent controls.

When Rahstahde Pledge enters, you may return target instant or sorcery card from your graveyard to your hand.

When Vicious Shamshir enters, you may attach it to target creature you control. If you do, target creature can't block this turn.
Equipped creature gets +2/+0.
Equip {3}

As long as it's your turn, Rallying Rector has first strike.
Whenever Rallying Rector attacks, you may discard a card. If you do, search your library for a card named Rallying Rector, reveal it, put it into your hand, then shuffle.

Equipped creature gets +2/+2.
Equip {3}

Colossal 2—{4}{G} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {4}{G} as a sorcery: Put two +1/+1 counters on it if it has none.)
Reach

Sacrifice two lands, Mill five cards: Return Jack, Horrific Harvester from your graveyard to your hand.
[+1]: You gain 2 life and each opponent loses 2 life.
[–2]: Return up to one target creature card and up to one target land card from your graveyard to your hand.
[–2]: Each opponent sacrifices the nonland permanent they control with the greatest mana value among permanents they control.

You may have Fleeting Memory enter as a copy of any creature on the battlefield, except it has “At the beginning of the end step, exile this creature.”

Each opponent discards two cards. If you control a Knight or Soldier, each opponent loses 2 life and you gain 2 life.

Shimmering Seadragon gets +1/+0 and can't be blocked as long as you control a legendary creature.

Enchant creature
Enchanted creature loses all abilities and is a blue Wizard creature with base power and toughness 1/1.