msem-instigator

If a player taps a nonbasic land for mana, that land produces {C} instead of any other type.
Whenever Rylei Wakebreaker attacks, it and another target creature you control each get +1/+0 until end of turn for each attacking creature you control.

When Silvercrest Historian enters, scry 1, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)
Draw a card.

Whenever Whisperer of Fortunes attacks, the next card you foretell this turn costs {0} to foretell.
Whenever you cast a foretold spell, put a +1/+1 counter on Whisperer of Fortunes. It gains flying until end of turn.

This spell costs {1} less to cast for each creature you attacked with this turn. (Those creatures don't have to still be on the battlefield.)
Flying

Enchant opponent
Creatures enchanted player controls get -1/-0.

The next creature spell you cast this turn may be cast as though it had flash and costs {1} less to cast. If it entering the battlefield causes a triggered ability of it to trigger, that ability triggers an additional time.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Flying
{2}{W}: Prevent all damage that would be dealt to and dealt by creatures with counters on them this turn.

Enchant creature
Embody (Enchanted creature is a copy of this card except for its types.)
Whenever Fate of the Weary becomes tapped, create a 0/1 black Spirit creature token with flying.

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.
Zombiecycling {2}{B} ({2}{B}, Discard this card: Search your library for a Zombie card, reveal it, and put it into your hand, then shuffle.)

Prevent all combat damage that would be dealt to you this turn. Populate. (Create a token that's a copy of a creature token you control.)

Whenever another creature you control enters, you may upgrade Relitian Renegade. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Ward {2}
• Flying
• Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

When Lingering Guide enters, mill two cards.

Lifelink
{B}, Sacrifice Lostrite Evoker: Add {B}{B}{B}.

When Bastion Warden enters, exile target creature an opponent control until target enchantment you control leaves the battlefield.

Whenever a player casts a spell, that player reveals cards from the top of their library until they reveal two land cards, then puts all cards revealed this way into their graveyard.

Flip a coin until you lose a flip or choose to stop flipping. Exile the top X cards of each player's library, where X is 1 plus the number of flips you won. You may play those cards until the end of your next turn, and you may spend mana as though it were mana of any color to cast those spells.

Choose a card name, then reveal the top five cards of your library. You may put a card with the chosen name into your hand. Put the rest on the bottom of your library in any order.
Draw a card.

Exchange control of two target creatures. If an opponent gained control of a Monk you controlled this way, return that creature to its owner's hand.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Instant and sorcery spells you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Once each turn, when Vedu, the Deepdrinker enters or you attack with one or more Horrors, you may tap up to two target permanents. If Vedu isn't a token, put two stun counters on each of those permanents.
{2}{U}{U}, Discard Vedu: Create a token that's a copy of Vedu, the Deepdrinker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

You may play lands from your graveyard.
{B}{G}, Sacrifice three lands: Return Endrison Nourisher from your graveyard to your hand.

Outfitted Ibex has menace as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Prevent all combat damage that would be dealt to Armored Axewarden as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)