msem-instigator

[+1]: Create a 1/1 colorless Thopter artifact creature token with flying. It gains lifelink until your next turn.
[–1]: Sacrifice an artifact. If you do, draw two cards.
[–6]: Draw seven cards. Artifact spells you cast this turn cost {2} less to cast.

Flash
When Witch of the Veil enters, if it was cast, you may sacrifice a creature. If you do, return that card to the battlefield under its owner's control.

Enchant creature
Enchanted creature gets +2/+2.
When enchanted creature dies, return it to the battlefield under its owner's control.

Look at the top two cards of your library. Put one of them into your hand, then submerge the other. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Enchant creature
Enchanted creature gets +2/+2 and attacks each turn if able.

Vial of Ice enters tapped.
{1}, {T}, Sacrifice Vial of Ice: Tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Reach
When Automated Overwatch enters, create a Function token with “If this spell would create one or more tokens, it creates twice that many of those tokens instead.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

If a source would deal damage to a creature in Cascading Zhenzu's pack, prevent 1 of that damage. (Two or more creatures you control with equal power are in a pack.)
{U}: You may switch Cascading Zhenzu's power and toughness until end of turn.

Ralora, Unforgiving Depths enters tapped.
Whenever a source deals damage to you, put a creation counter on Ralora.
{T}, Remove ten creation counters from Ralora and sacrifice it: It deals 10 damage to target player or planeswalker.

{T}: Add {G}.
Concord — {T}: Add two mana in any combination of colors. Activate only if there are four or more card types among permanents you control.

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.

Each creature you control gets +1/+1 for each other creature you control with the same name.

Sacrifice another creature: Blood Bairn gets +2/+2 until end of turn.

Stampede — Whenever Etlan High Priest and a creature with greater power attack, Etlan High Priest gets +1/+1 until end of turn. Then you gain 1 life and scry 1.

{T}, Pay 1 life: Add one mana of any color that a land an opponent controls could produce.

Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)

Lifelink

Return target cryptic card from your graveyard to your hand. (Artifacts, enchantments, and modal spells are cryptic.)

Vigilance
Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

Target creature you control gains indestructible until end of turn if it's embattled. Then it fights target creature you don't control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, if you control three or more creatures, Traveling Scholar gets +1/+0 until end of turn.

Whenever you cast a noncreature spell, you may put a progress counter on Hellbent Speed.
[PROGRESS 2+] Noncreature spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.
[PROGRESS 6+] Whenever you cast a noncreature spell, draw a card.

Flying, deathtouch
When Bloodsucking Pihuchen enters, choose a nonland card name.
Whenever a permanent with the chosen name enters, each opponent loses 1 life and you gain 1 life.

{1}, Sacrifice a creature: Desperate Forsaken gets +1/+1 until end of turn. You gain 1 life.

Gain control of target creature.