Finally beat mysterio on 6.3.5
When I got to him I had 3 champions left 5star Howard, the duck, Joe fixit and sentinel I switched out Joe “who was very low on health” for my 7star Ebony Maw (who I was taking in for kicks and giggles because I never used him before) and I was able to beat him with heavy attacks and had to use 1 revive.
So now I can more on.