High Market

{T}: Add {C}.
{T}, Sacrifice a creature: You gain 1 life.

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Star Athlete

Menace
Whenever Star Athlete attacks, choose up to one target nonland permanent. Its controller may sacrifice it. If they don't, Star Athlete deals 5 damage to that player.
Blitz {3}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Marvin, Murderous Mimic

Marvin, Murderous Mimic has all activated abilities of creatures you control that don't have the same name as this creature.

Hellrider

Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it's attacking.