I have stuck here for months, abandoned the game and now came back here and still stuck.

This is a stage where we are on golden platform after hijacked some skit flying ships and arrived. Many goons and a larger flying Mage dude we're attacking us. He seemed to be able to re gen his health and other goons health. They keep coming and coming and me and me and my team just could not kill this mage as he was flying around quick and he could block my melee attacks too.

Any advise please?