Having a very hard time with event

Psychicgallery

Hi everyone, I have been playing for about a week and a half I am level 26 and currently am equipped with dark Templar blade adventurers helmet and wind callers shield.
I can't seem to hold enough life or shield to get through main bosses in these waves. Any ideas? The only other equipment I have is the fire shapers set. I have sold everything off to get coins to upgrade training center.