This very much reminds me of Dreadknights tbh. BUT! I will say this, as a core Mystic player and one of their leaders I got to say that I don’t think Mysticism would be involved in this type of creature. Mostly for the fact that we dont really want another type of creature like that. We have (or used to) have Paleknights which were just Stone Knights, and I am pretty sure in our rewrite we will try to bring them back in a different way then they were. Plus we also have Gravens so another Warrior-type creature for us I dont think is entirely needed and just adds more bloat.
Necromancy is also shelved so all you have left is Blood Magic, which had Dreadknights long ago (I played one) and this is pretty similar in the core function of them. The whole ‘gotta stay in armor. Im tormented and in pain constantly! The runes bind me to this metal coffin!”
Overall I just don’t see it as necessary. Especially how LT is wanting to purge all unnecessary shenanigans. I do encourage you to keep writing though! And coming up with new ideas. I just have to say No to this particular one.