Kastral, the Windcrested

Flying
Whenever one or more Birds you control deal combat damage to a player, choose one —
• You may put a Bird creature card from your hand or graveyard onto the battlefield with a finality counter on it.
• Put a +1/+1 counter on each Bird you control.
• Draw a card.

Black Panther, Wakandan King

First strike
Survey the Realm — Whenever Black Panther or another creature you control enters, put a +1/+1 counter on target land you control.
Mine Vibranium — {3}: Move all +1/+1 counters from target land you control onto target creature. If one or more +1/+1 counters are moved this way, you gain that much life and draw a card.

Mendicant Core, Guidelight

Mendicant Core's power is equal to the number of artifacts you control.
Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
Max speed — Whenever you cast an artifact spell, you may pay {1}. If you do, copy it. (The copy becomes a token.)

Mathas, Fiend Seeker

Menace
At the beginning of your end step, put a bounty counter on target creature an opponent controls. For as long as that creature has a bounty counter on it, it has "When this creature dies, each opponent draws a card and gains 2 life."

Chromium, the Mutable

Flash
This spell can't be countered.
Flying
Discard a card: Until end of turn, Chromium becomes a Human with base power and toughness 1/1, loses all abilities, and gains hexproof. It can't be blocked this turn.

Sharuum the Hegemon

Flying
When Sharuum enters, you may return target artifact card from your graveyard to the battlefield.