I was running faction wars last night with Orcs last night and when it was Galek's turn instead of attacking he chopped off Artak's arm on my own team and then left the battle? I looked through their skills to see if I missed a synergy to see if I gained something from it but when I looked at Artak's buffs all that I saw was that he had one instance of "Brooding and moping". Not sure what that is all about. 

All joking aside, I am pretty sure that Siphi's passive was still activating in arena even though I had a block passive buffs from Ronda applied.