Since my polymorph meme has only garnered three downvotes so far I thought I'd offer a bit more controversial take, and see if I can manage to stir the pot a bit with this one.
Since my polymorph meme has only garnered three downvotes so far I thought I'd offer a bit more controversial take, and see if I can manage to stir the pot a bit with this one.
I fail to see how that's supported by RAW. If damage reduces you to 0 hit points and fails to kill you, you fall unconscious.
The fact that a Fighter subclass gives you an ability to act otherwise doesn't affect this, any more than you could say you stay conscious at 0 because Zealot Barbarians can do it. You don't have that ability. You're unconscious or dead when Vampiric Touch triggers. Vampiric Touch fails.