The problem seems to be in the interaction between cunning/poisons/toxic death and brittle clear ooze (in this case I found it in the "Old Conclave Vault")
First a screenshot:

What lead to that was I think toxic death splitting the brittle clear oozes across the entire screen, doing normal damage (22 per turn), once the room was completely full and the oozes were about to mass die from the poison, somehow it just explodes, usually the first turn doing normal damage (22), the second turn doing 3k, third turn doing 20k, then the fourth turn doing 300-500k.
Normally I wouldn't complain about this, but for some reason the damage also reflected onto me, one shotting me for 500k damage, according to the log, this was an ability of one of the ogres so it may not be a bug. I have attached the log in this post, I copied the log about a couple of turns after death, so this should be seen a couple of screens up.
Note: Log is too large to be uploaded, but here is a dropbox link: https://dl.dropboxusercontent.com/u/343 ... e4_log.txt
Edit: The source of the poison that is exploding actually came from that spydric cloth armour, I forget the name I already transmogrified it.
http://te4.org/characters/102931/tome/4 ... 53409413a7