The strongest advice I can do is, dive characters you use that gain new skills after diving them (i.e. Quistis can gain Black 5) or characters that gain a great synergy with their relics (i.e. Celes Spellblade 6 and Indomitable Blade), after that, go for favourites. Imo Diving Tyro is useless, his stats will still suck unless you are completely sure that he will be a lot in your party.
I dive and level to 99 characters I have BSBs or great relics for - OK, Luneth, Cecil, Ramza, Tyro. Beyond that, its unlocking skills.
Tyro was my first dive, I use him for literally everything (due to a combination of Wall and a self indulgent custom sprite) so attempting to close the stat gap even a little bit vs other un-dived characters is worth it for me personally.
The stat increases may seem relatively minor, and they'll never close the gap entirely, but the bigger deal with Tyro is the fact that his record dive places further emphasis onto what his Record Materia did; Tyro is designed to exploit weaknesses.
+6% spellblade damage, +9% black mage damage (and +9% white mage heals), and +9% damage vs weakness go a decent way to closing that gap.
Next dive I'm doing is mah boy Gilgamesh. Need him to have Dragoon 5.
I Record Dove Pcecil to boost his sword damage for extra unfairness and Faris to give her 4* Machinist skills for offensive support Queen status, with a little bit of dabbing with a few other characters I had good SBs for/characters I like like Basch and Yuffie and Beatrix.
Problem is it ruined my 4* Dex mote cache boosting all those physical characters so now I can't finish up Luneth or OK or really any physical characters for quite a while. Was considering dropping more Mage motes on OK but I only have his Slicer and I'm gonna be pulling hard on the 14 banner for both Yshtola and Alph BSSBs so I'm gonna wait.
Thanks for all these responses!
Basically when I came back to FFRK, one of the first tips I was given is to save up all motes for Onion Knight.
I've gotten several bsb relics for characters such as Tyro, Pcecil, Greg, Selphie, Faris, Ramza, Vivi, etc, etc
It's hard to pick one that you know will be a worthwhile investment, but I guess it will be moot once 4* motes become farmable later
I'm leaning towards Tidus for his BSB/OSB but his record dive only offers +3% water damage and 3* spellblade which isn't much (I typically do 80k-90k OSB in ultimate fights with BSB enwater active and record dive +water damage would only add 3k-4k more to that which is trivial compared to unlocking 5* abilities for other characters
