Stay diagonal to Ironblights and Orewalkers, they both have beams. Orewalkers have a thin manadrain wave.
Focus on killing Versperoth and do not worry about the minions. The time spent killing minions will mean less damage to the boss and more time dealing with the minions.
Cover Versperoth's room in Energy Fields, have your team spread out on the fields and move around when the minions spawn. This way, the golems will not melee you and, if positioned properly, they won't beam you either.
Watch your health because there are many sources of damage in Versperoth's room: each lava golem is capable of dealing more than 1000 damage with just beams, and Versperoth's massive fire attack hits everyone near her for up to 700 or more.
Abyssador attacks very wildly and this makes him harder to control. It is imperative that he is blocked to protect your shooters.