Persona x Tales?
I'd buy it in a heartbeat, but I don't think I'd like it.
What I love about Persona is the music (Honto No Kimochi & Snowflakes) and laid-back relationships you form with your friends and the town (Marie and Elizabeth P3 requests). Although, I couldn't play a Persona game that's pure VN-story.
What I love about Tales is the battle system and exploring new towns and areas.
If I combined the two then, hmm... A JRPG with a battle system that leans to Tales. You have a blank-slate male/female MC and the party walks around with you in the overworld, but you can't switch characters. The general pace and narrative would be slower paced and you'd spend a lot more time in the towns with personal quests with the citizens.
The monsters you'd fit in battle could be recruited to your MC's stable through negotiation and summoning them would be similar to performing high-tier Artes.
Maybe, but I don't see how it could mix together. I'd hate it because the battle system is so speedy, but the narrative moves too slow. I'd love to monster recruiting, but hate the fact I can't switch characters or let my other party use them (4 of us + our monsters + the enemy = Too much on screen).
If Mother 3 didn't take itself so seriously and Xenoblade Chronicles had less monster-quests and more missions with your party then those two might be close to what 'PERSONA X TALES' might be.