The new Vampire character's bite ability seems to be bugged. It began at 1 damage, and after the first use decreased to 0 damage instead of increasing per the character description. Can't wait to try him out once that's fixed!
Should probably make it so it can't go below 1. Because if you don't somehow miraculously realize that's how it works on your first ever use. Then the skill becomes useless for the rest of the run, which is what happened to me as well. I used it after a trap revealed multiple enemies, which did kill one of them, but didn't kill the rest. Which triggered the halving like 3 times and set damage to 0 instantly, killing the run, since late game you need your skill to do stuff, as enemy hp outscales weapon damage/charges.
Knight experience was solid though, won on my first run and everything worked as expected.
This still seems to be bugged for me. With only a single 1/1 enemy on the field, I used the bite ability. This killed the enemy but still reduced the skill power to 0. If the description of the skill says that it gets stronger after every use, having it get weaker for any reason seems strange.
Edit: I intentionally tried killing two enemies at the same time to see if that helped, but it still reduced the skill power to 0.