#1 There are four "Omnitron bosses". They all throw up a shield now and then, and when they do you start DPS'ing the next boss.
#2 Tanks should tank arcanotron away from the power vortex, and the raid should stand inside the power vortex to get buffed. Tanks should also lure Toxitron to stand in his own poison cloud.
#3 When you get the "Lightning Conductor" debuff, and when you get marked by Magmatron: Move away from the raid.
#4 Don't stand in fire, don't stand in poison clouds, kite adds