How to make Solo play Easier once u hit level 70+ ?

So I’m a fire Wiz level 75 and I’m in Avalon and these bosses are getting ridiculous starting with max pips so when they go first it’s devastating…My strategy of blading up then attacking with fire dragon isn’t working anymore because they use defensive Auras and shields and around that time they already took 1500+ health from me I’m actually confused I don’t know what else strategies to do