How to beat this boss I'm struggling here
It all depend what heroes you have.
I am using Zephy, Dove, Walla, PD and Occultist. Imo most important part is to keep your heroes alive, and heal them as quickly as possible. You can use 2 healers to achieve that, but also you need good friend to help you. There is nothing worse than friend which will not help you, cause his heroes will die in first few seconds.