Disclaimer: I will not focus on Art or grammar, unless the latter would make the deck too difficult to understand.
Okay, this one for some reason didn't appear on the "Submissions in need of rating" list, so nearly missed it.
It's a nice NPC concept for an encounter, though one that might depend a bit on the table and all. Clear gimmick too, and I appreciate the mechanics and consistent aesthetic involved. I'm quite curious on how you picture the mechanics to look like in terms of appearance and animations in-fiction?
I don't actually disagree with Mateoboio's assessment about defenses+burn being quite the combo, though, even if I am probably slightly less worried. It'd definitely have to be tested in practice. That said, {Blocker} Items being plentiful can become really frustrating to deal with as a concept for the reasons mentioned and feeling like no progress is made if dice luck gets bad?
Good job!