I was just running Ascalonian Catacombs Story Mode and on the necromancer boss right toward the end of the battle I my skillbar changed and I had a different #1 and #2 skill that I assume are her skills. I was also unable to remove the skillbar but it finally went away after being downed. I believe arcane thievery caused the bug. The life-siphon skill she uses on her minions may be considered a boon and arcane thievery transfered it to me and in some odd way I received her skills? Thats just my hypothesis. Its also possible that this was intended but I highly doubt that so I figured it would be best to report it. Pics are attached.
