If you choose a Persona that you already have, then all Personas who share the same Arcana will gain experience.
[uf 0 5 65278][uf 2 1][uf 4 8 32]If you choose a Persona that you already have, then all Personas who share the same Arcana [uf 0 1 2]will gain experience[uf 0 1 27].[n][uf 1 1][e]