it is really hard on ps3 to beat this boss in nhgitmare. in my nhgitmare difficulty he hit me with electric shocks but for some reason he doesnt do it on your playthrough. i had 0 electric resistance so his attacks did alot of damage. your tank damage deals aswell whereas aveline in my playthrough was pure tank and my rogue used to deal alot of damage same as varric so he kept running to me and varric. it was really tough it took me an hour.