[Coda]

@hyjin, at this point my recommendation is still to concentrate on leveling up and ranking up. Team cost is going to be your limiting factor for quite some time (though go look at the quests in the "other" menu so you can get the Team Cost awoken badge!) so really it's going to be a question of what teams you CAN build rather than what teams are BEST.

That said, the High Ninjas are FANTASTIC early-game subs due to having ridiculously high ATK relative to their team cost.

Given that you're probably mostly team-cost constrained, I'll just suggest leaders for mono-color teams, and you can pick the subs that go underneath based on what fits.

Fire: Ifrit
Water: Plesios (more offensive), Pianis (more defensive)
Wood: Verdandi
Light: Saria
Dark: Yukari

You can also use Ifrit for a mixed fire/water team with reasonable success but I only recommend that if the dungeon you're going up against is mostly wood-element with a few water-element opponents getting in your way.

If you run Plesios as a leader, I strongly recommend putting Cleopatra as a sub beneath it; Ifrit is also a reasonably good sub there.

You have enough low-cost Devil types to make Shishio a viable leader, but unfortunately that team would have very low RCV, so you'd have to be careful with it -- it would be a very aggressive team that can't take many hits.

The Kenshin collab has left you with a TON of Attacker-type monsters, so a team led by cao cao would be pretty strong.