Hardmode is same thing as normal but tighter enrage/more HP/more damaging abilities it is very simple just need to bring 1 tank/2 heals/5 dps and should have no problems. Only fight I saw with a difference was the puzzle boss you can't click the console over and over you get a cool down and need to rotate.
If you are having trouble hitting enrage on first boss in EV just stack up for the mortar volley thing when he sits down and hits everyone use aoe heals and personal cooldowns this strat worked for a BH heals/Sorc heals comp.
Re-reading my post I guess I failed to mention I'm talking about Flash Points. My apologies.