>>542938150
Fair warning that a lot of those characters that you've seen a lot and might want to acquire are genuinely bad for combat purposes these days and the game can be kind of a massive slough if you are just trying to do your dailies and overworld bosses with a Yoimiya, Raiden and some 4 stars. It's worth pulling for a newer, stronger character at least once because the increase in power is unbelievable. But you don't really need more than one team that is mathematically strong if you're just screwing around.
Don't worry about Spiral Abyss or imaginarium theater for a while after first starting out. Stygian abyss however is basically free to clear at the low difficulty for easy gems.