Put this in your head - imagine you were an employee to design an old feature, aka the Pair Skills from P3FES, how would you design them? What Personas would you use? What skill(s) would you reuse from the third game? IMO, I would honestly use Infinity, with using the original Vishnu and Ananta, but I'd also use Asakaro and Zanada, the reawakened Fools of the wildcard team member I was talking about. Rank 3 would be when I allow the pair skills. If I was to make my own, it'd be with Weibu and Ashira, raising the Defense and Attack of everyone in the group. It'll take 24 SP if you use both, and if you reach rank 10 for Shared Heart, 48 SP when using only one. But those are my thoughts, I'd like to hear yours.