[@NarcissisticPotato] Jack Harkness's is from torchwood the series. Think doctor who. He was immortal. He couldn't actually die per say. What would happen is that he would take damage then heal from it. He got buried alive and survived and even got blown up. But his body just regrew itself by clawing it's self back together then healing what it couldn't claw back. I'll see if i can find the scene on youtube one sec 

I am a massive marvel nerd, BTW.