Summary: Kargra Raythe will not leave his room / will not attack if you get out of range, but you can continue attacking him on Cathedral Level 2.

Not sure if this is entirely a bug, but it seemed strange that this magical creature was unable to chase me into the hall. In fact, I was just able to stand in the hall hitting him with ranged items without getting attacked or anything, his avatar seemed frozen but his health was going down.

On an additional note, my summoned creatures (zombie dogs in this case) would also not enter this room, before or after Kargra was defeated.

Kargra not leaving / summons not entering:
http://waddz.net/BugScreenshot000.jpg

Map Location:
http://waddz.net/BugScreenshot001.jpg