Deathtouch
{1}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness.
{1}{W}{B}, Sacrifice another creature: Exile target nonland permanent. Activate only if you have at least 10 life more than your starting life total.
Once you’ve announced either activated ability, it’s too late for anyone to interrupt you by trying to remove the creature you sacrifice.
Once you’ve legally activated the last ability, it doesn’t matter what happens to your life total.
Your starting life total is the life total you began the game with. For most two-player formats, this is 20. For Two-Headed Giant, it’s the life total your team started with, usually 30. In Commander games, your starting life total is 40.