Partner with Cazur, Ruthless Stalker (When this creature enters, target player may put Cazur into their hand from their library, then shuffle.)
Ukkima can't be blocked.
When Ukkima leaves the battlefield, it deals X damage to target player and you gain X life, where X is its power.
If the target player is an illegal target by the time Ukkima's last ability tries to resolve, the ability won't resolve. You won't gain any life.
17 Apr 2020
Use Ukkima's power as it last existed on the battlefield to determine how much damage it deals and how much life you gain. If that number is negative, it deals no damage and you gain no life.
17 Apr 2020
If your life total is brought to 0 or less at the same time that Ukkima is dealt lethal damage, you lose the game before the last ability goes on the stack.