Phylacteral Link mobs dont lose the Bloodlines mod and cannot die.

Hello, I recently encountered a bug, but entirely sure what caused it.
The mobs haev Phylacteral Link bloodlines mod (the little disc aura as seen in screenshot) but the mod doesn't appear in description and they actually dont get a big disc so they cannot die.
This could have happened because there was a rare monster near them with 'allies cannot die' mod on it and the magic monster currently targeted by the big disc of Phylacteral Link got to 1 hp with the cannot die aura on it.

http://i.imgur.com/LUS9HWn.png

Hi, had the same issue, just in front of Merc Piety. 8 PL tentacle miscreations, wihtout the mod displayed or the disc, I ran around a lot with them trying to find the one w the disc, but eventually had to give up killing them.

I've had the same issue for me once or twice.
This is the last mob left from the map, as well as the strongbox.

http://i.imgur.com/216egMm.jpg