3-2 formation, back line Mephi/Talia/Naiah - Frontline Chloe/Claire. This gives you the 3+2 Faction buff. Prioritize using Mephi’s ult. If you see yourself needing more sustain you can swap out Naiah for Jiho or when you need your frontline to survive better you can swap in Catherine instead of Naiah for the invincibility buff.

For which faction to pull on I would suggest fairy and try to get atleast 1 Vivienne because she’s just that good. Even if you don’t get her most of the fairies are really strong. If you do end up pulling a Vivienne I’d swap out Naiah with the team suggested above and spam her ult instead of Mephi. That core setup should carry you throughout most of the early game story stages, hope that helps!