So it appears that the zealot in Darktide is supposed to be able to have a similar playstyle that can be done with Zealot in Vermintide 2, that being deliberately get down to 1 hp and live completely off of temp hp/toughness. Enemies that do corruption damage as a portion of their damage will bypass toughness and immediately down you if you’re very low hp even if your toughness is full. It feels really bad for a hit from a pox walker to sneak through and proc Until Death, or get clipped by a tox flamer you didn’t see.
Perhaps if the Zealot couldn’t be downed by corruption damage alone? Or perhaps have the corruption damage not affect your current hp until it begins to overtake it. (I.E. lets say you have hp pool of 100, and you have 40 hp currently. your HP would stay 40 until the corruption dropped your max hp below 40, at which point it would damage your HP normally).
I don’t know if either of those ideas is a suitable solution, but as it is Until Death feels really bad, being downed by corruption damage while having low corruption and max toughness feels bad, and Honour the Martyr seems like a bad feat/playstyle to spec into because of it.