Here is a pretty good tool to use, to check if your dream team gonna work or not.
I would recommend to use goolge trans. on this:
Combo Simulator

if the char's don't load in, that only your Protagonist/Class shows > press the Yellow reset *on,
that usually fix the problem.

if you see chars, with Blue text over their stars, that means their skills can be upgraded.
So if you click the Blue text, then you will get the upgraded skills UI.

FYI: the filter search on chars, don't really work with google trans. it might stop working then, so u might need to turn off/on the trans or press the Yellow reset *on again.... or maybe even refresh the site/F5 :P

Yeah it is.
Also remember to set your Protagonist/Class skills + Pets:
http://i.imgur.com/L9xjsi6.png