Firstly, using Command Staff with Penitence and trying to change its element makes the game freeze up and creates endless LUA errors - when it happens, I can't close the Command Staff window because rolling over any of the options creates a LUA error.
The second bug concerns Oozewalk, which appears to remove beneficial status effects as well as bad ones. I don't think this is intentional; as it is, it's not really playable if you don't know if it'll remove your stun or your regen.
The third bug, if it is a bug, is that whenever anyone other than the player character casts Flame, my game lags for about a second. It's trivial but noticeable and occasionally makes me think "Oh jegus have I just died

The fourth thing is not so much a bug as an endless, easily fixable annoyance inherent in the game: Celia's Still-beating Heart. It takes about ten seconds to recharge for me, or a lot longer if there are monsters actively moving around in the stage I'm in, which just makes playing Necro incredibly tedious. I recommend that the cooldown is reduced significantly, or that the soul-producing effect of the item is simply removed entirely; this would make Necro's soul economy harder but much more interesting! Animus Hoarder would actually be useful again
