Say, If Truvia and Serpico become playable(with there Etheric Other), what will be there Attribute, Specialty, and how they act as supports for Pyrios(aka: Phaethon's Stand/Persona)?

I know it's too early for speculations like this, but I'm very curious on how they'll function together as a team, whether their kits synergies, similar to how the Angels of Delusion members synergize well with each other.