msem-instigator

Haste
Whenever Rapid Rodent attacks, it gets +1/+0 until end of turn for each other creature you control with flash and/or haste.

Whenever one or more other creatures you control deal combat damage to an opponent, choose one —
• That player discards a card at random.
• That player sacrifices a creature with toughness 4 or less.

Ravenous Attraction enters with a +1/+1 counter on it.
Whenever a creature you control dies, double the number of each kind of counter on Ravenous Attraction.

The second spell you cast each turn costs {2} less to cast.
Whenever you cast a spell, each opponent loses 1 life and you gain 1 life.

Tap X untapped Shamans you control: Ravik, Still-Smoke Seer deals X damage to any target and you gain X life.

Flying
Whenever an opponent discards one or more cards, fateseal 1. (To fateseal 1, look at the top card of an opponent's library, then you may put it on the bottom of that player's library.)

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Scry 2, then draw two cards. You lose 2 life.

Death knell — You may sacrifice a nontoken creature. If you do, create a 3/3 black Spirit creature token. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Creatures you control dying causes their death knell to trigger. (In addition to the normal death knell trigger.)

Draw a card for each creature you control with a permanent attached to it.

Put four time counters on target nonland permanent. If it doesn't have vanishing, it gains vanishing. (At the beginning of your upkeep, remove a time counter from that permanent. When the last is removed, sacrifice it.)

You may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of lands you control.

Whenever a Plains you control enters, you may put a creature card with mana value 2 or less from your hand onto the battlefield.

Gain control of target creature until end of turn. Untap that creature. It gains haste and defiance until end of turn. (Whenever that creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)

Exile the top card of your library and up to one target permanent card from your graveyard. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Exile target instant or sorcery spell you control. Until end of turn, you may cast that card from exile without paying its mana cost. When you do, copy it. You may choose new targets for the copy.

Draw two cards. You may play an additional land this turn.
Coalesce {5}{G}{U} (You may cast this from your graveyard for {5}{G}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Trample
When Reckless Exemplar attacks, if its power is greater than its base power, target creature an opponent controls can't block this turn.

Exile the top three cards of your library. Until the end of your next turn, you may cast nonland cards exiled this way.
{3}{U}{R}: Return Reckless Experiment from your graveyard to the
battlefield tapped and transformed.

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
When Reckless Guardian dies, create X 1/1 colorless Servo artifact creature tokens, where X is Reckless Guardian's power.

Haste
Whenever Reckless Pyremage becomes tapped, it deals 1 damage to each creature and each player.

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Flash

Hexproof
Paranoia {1}{U} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Return target permanent to its owner's hand. Then that player discards a card.