Need help for team composition

For wave clearing, I recommend Fran, Nitocris, Da Vinci and Friend support Waver, with the right CEs you can annihilate a few good continuous rounds of enemies with continuous NP spam.

For bosses, Herc, Ozy, Kintoki and again, Friend support Waver will do you absolute freaking wonders. (Again, with the correct CEs and skill usage, you can spam one NP after the other)

That's what I would recommend at least, as these two type of team comps has saved my bacon many times in this game.

Out of curiosity, are you F2P? Because that is an absurd amount of 4 star servants in only 3 months of playing (I started in a similar time span and only have four 4* servants)

I wouldn’t ignore Liz. She is very basic but with a team attack buff and an enemy defense down, she can really assist your damage dealers. And if you can’t swap her out in time she has guts to keep her alive. She is good very clearing mobs. Nitocris can spam her NP but it relies on causing death as otherwise it is extremely weak, even for a caster AOE NP. DaVinci will be much better at clearing harder waves as a lot of stronger enemies are very resistant to death