He has so many artes that it's hard to imagine how they could all be incorporated into just special moves. I could imagine maybe he'd have like a Base and Arcane arte assigned to each special input, depending on whether he was comboing into it or what. It's definitely hard to imagine him not being a super combo oriented character though, just given Tales being what it is.
I can see Sword Rain, Tiger Blade, Demon Fang, Rising Falcon, Tempest, Beast, all sorts of stuff being too good to pass up. And while I do think that it's not impossible for a Unison Attack to be on his kit somewhere, for my money he will 100% have Falcon's Crest. It's his Mystic Arte, and Mystic Artes are some of the most iconic Tales things out there. Like, I expect a full on cut-in and everything. I feel like it makes the most sense on his Final Smash, but honestly I wouldn't be completely shocked to see it be something you can somehow "combo" into, probably under really strict and specific circumstances.
Man, just thinking about the possibilities is pretty dang fun. I really hope that even if he doesn't make FP5, he'll be post-pass DLC.