Apparently you don't think spawning Arch-viles and Revenants on wave 5 is evil enough. (This could be an issue with the way Infinite Arena is designed, however: the spawns themselves could use some scaling. Right now it appears that there's either some kind of "total difficulty" that determines what and how many can go it, or a weighting and changes based on the wave. Either way, there's got to be a ceiling for certain enemies, both in this and Patience.) The lack of real, solid pillars is actually a problem most of the time, especially when it comes to Revenants and Mancubi: it just gives units with range another advantage on you.
I can understand why Pain Elementals were taken out, but wouldn't it also be possible to introduce a health ceiling? The original certainly has one. 500% health was pretty fun to have, though.
The Armor of Contempt, if anything, is a major hindrance later on (and by that I mean, starting around wave 5). Three armor really doesn't cut it against punchier enemies. What we're looking at is a Necroarmor that is inferior in every way, only SLIGHTLY helped by the fact that you gain health after every kill. Give some knockback and movespeed beneifts (like the real one) and it might actually be worth something. I'm glad it's destroyable, though, maybe it'll eventually just wear out after a hard enough battle.
Obviously we're looking at a melee build here, but to what extend I'm not exactly sure. Vampyre seems redundant (is the extra 3 worth it when you already get 5?) but has knockback beneifts that could reeeeeealy come in handy. Blademaster has Hellrunner, but that does nothing for Revs. I'm almost tempted to start with a single point in Brute and work my way to MFa, what with the tons of splash you have to deal with.
EDIT: Oh, nevermind, you did introduce a health ceiling. Guess I know what to get then...