Siege Dragon

Flying When this creature enters, if your life total is less than your starting life total, it becomes equal to your starting life total.

Whenever you draw a card, put a +1/+1 counter on this creature. When this creature dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on this creature. (They can't be blocked as long as defending player controls an Island.)

Artifact spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting an artifact spell pays for 1 or one mana of that creature's color.)

You may have this creature enter as a copy of a creature you control, except it has "2UU: Return this creature to its owner's hand."

Destroy all creatures you don't control and all planeswalkers you don't control.

Destroy all creatures you don't control and all planeswalkers you don't control.

Flying At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature of their choice or pays 3 life.

Flying, trample Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life. Whenever another creature dies, put a +1/+1 counter on Ob Nixilis.