Do you have Ultimate Galek by any chance?

how is drexthar geared, that team may be able to auto 20 with proper gear on everyone. you may need to manual the other stages but 20 as spirit with drexthar tanking in lifesteal w/warmaster and the defensive counter mastery maybe?

In my point of view you have a difficult time doing it easily, my advice is to focus on:

Using drextar with books and a lot of resistance so that he does not die from poisons and he can debuff as much as possible.

MM for team survival.

Cold heart for damage and reduce turn bar.

Now with those 3 safe, you would need something that lowers defense, turn bar or increases drex survivability