The Chosen Ones

please help me out if there is any bug in my fight with yugrimar(bone dragon) chapter 9 v2.0c
           In first phase the fight seems normal yugri summon skeletons and the impale ward stick yugri keeps flying up and land on you plus he is heal completely when he comes back down this keeps happening i just keep going with the same cycle then suddenly cinematic which show i beat the 1st phase even thou his heal is full(i take his health about 75% before flies up and comes down all healed).
           2nd phase four corner rooms with yugri center the 1st 4 summons need to be killed before the rooms open up after the they keep respawning indefinitely, once you choose a room all 3 heros need to be there in that room before cooldown else the hero outside room dies, i choose the room in order 1-no evasion,2-no panel,3-no regen the fight was tough but normal fight heal fight.
           Last phase or something after the 3rd room all heroes need to be at the center before cooldown else they die(the ones that dont make it). now there are four yugri in each corner channel a spell and i loose health impossibly fast till you run to one of the yugri and fight him(gearloth hardly don't have time to run will die 3 time just to run from centre of room to one corner his health is 8k+). fight with yugri has a red star revolving under him once a while have to run away before it explode.repeat for all four and the fight is done.