User blog:Uniqueusernamer/Need help going from casual to hardcore player

I have no idea what I should run for a team. I've played this game casually for over a year now and have lots of units but no idea how to build a legit team. I have been going over some of the units to summon for the 30 day reward and I have some of them already but still not sure what exactly I need to have a good team.

These are my units: Ramna(G), Alpha(B)(A), Mariudeth(B), Miku(A), Toutestsu(A), Eze(A), Raaga(L), Mifune(B), Zergel(B), Michele(O), Kagutsuchi(G), Luther(B), Clair(L)(G), Caira(O), Lucia(L), Lune(B), Edea(A), Luly(G), Rosetta(L), Dion(A), Orna(G), Balgran(B), Thunderborn(A), Kira(G), Fadahl(G), Krantz(G), Yuuri(L), Shida(A), Ardin(B), Ivris(L), Reis(L)

Currently I run: (LEAD)Miku, Ramna, Alpha, Toutestsu and 4* Vargas for fill

I'm level 110 and have 140 cost. If anyone can please help me get an idea of what I can do to better my team that would be really appreciated! I still have not chosen my 30 day anniversary unit because I really don't know what I need to be successful yet.