Myrel, Shield of Argive

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.
Whenever Myrel, Shield of Argive attacks, create X 1/1 colorless Soldier artifact creature tokens, where X is the number of Soldiers you control.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Mabel, Heir to Cragflame

Other Mice you control get +1/+1.
When Mabel, Heir to Cragflame enters, create Cragflame, a legendary colorless Equipment artifact token with "Equipped creature gets +1/+1 and has vigilance, trample, and haste" and equip {2}.

Alesha, Who Laughs at Fate

First strike
Whenever Alesha attacks, put a +1/+1 counter on it.
Raid — At the beginning of your end step, if you attacked this turn, return target creature card with mana value less than or equal to Alesha's power from your graveyard to the battlefield.

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Chaos Wrap

The owner of target permanent shuffles it into their library. Then they may look at the top card of their library and may wrap it. If it's a permanent card, they may put it onto the battlefield. Otherwise, they may put it onto the battlefield face down as a 4/4 red Present creature. (To wrap a card, put it inside lots of sleeves. If it would be dealt damage or destroyed, remove a sleeve from it instead.)

Kaalia of the Vast

Flying
Whenever Kaalia of the Vast attacks an opponent, you may put an Angel, Demon, or Dragon creature card from your hand onto the battlefield tapped and attacking that opponent.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.