Help merge project

You might want to wait until 3.0 or even 3.1/3.2 depending on when the major, game-changing stuff comes.

Having merged Felicia to +6 I can tell you that without +atk she's a specialist. I can't squeeze out enough damage against armours with less merges than her even with buffs, even if they only have res in the 20s. I would need res ploy.

You want a powerful offensive hero? Reinhardt, Felicia (make sure she's +Atk) or Sothe.
You want an effective defensive unit? Effie or Sheena.

imo +10 Effie or Sheena is good for arena scoring and +10 Rein is good for PvE content

Agree with Seeker to wait, however the one exception is Reinhardt. He is a great tool for most chain challenges and all purpose maps