Just started a few days ago and am at ch10, a little lost now. I have an 11k team with mixed colors, and a 9k all water team. Should I keep trying to beef up the water team? Do you want to always focus on mono color teams?
I'd focus on the current Rhythmic Resolutions event since there's lots of material you can get that will help out with building your teams.
There's sometimes non-element events; but most of the time you're dealing with mono-element teams for Chapter and Event quests.
I'd probably focus on building teams in the following order:
- One Adventurer per Element
- One Adventurer per Affliction Resistance (Ex: 1x 100% Resistant Fire/Stun | 1x 100% Resistant Fire/Sleep)
- One team of 40 Mana Circle (MC) adventurers per Element
- One team of 40MC per Affliction Resistance
- One 49 or 50 Mana Circle Adventurer per Co-Ability (Ex: Blade/Strength, Axe/Defense, etc.)
One built adventurer per element should help you run co-op with players to clear tougher event content; I think getherwings tend to be pretty plentiful early on so you might as well take advantage of them. One built adventurer per affliction resistance will just help make content less frustrating.
Now that 3* Adventurers are given out for free; it should be easy enough to build a full team to 30 Mana Circles (MC) cheaply. The story adventurers Euden, Ranzal, Elisanne and Cleo are all great units that should help you up through late game content. Shadow and Light element have no weakness so I'd typically slot in stronger shadow units when needed.
4* Strength Dragons are your friend for a long time early on. Ifrit, Vodyanoy, Roc, Lindworm & Juggernaut made up most of my element teams until I had max unbound (MUB) 5* dragons to replace them.
Having one 50 Mana Circle adventurer (or 49MC if you don't unlock the Ingot) per co-ability will help you build stronger more flexible co-op adventurers since they give you bonuses if they're on you team.
Hope this is helpful. I'm not sure if this is the most efficient step by step; but it's the route I followed when I came back to the game.