Dissidia NT

[Nestama]

That brings up a concern gameplay wise as if Neal goes into "Eula loves Bahamut" mode, isn't that just edging in on Terra's gameplay when she goes all Esper?

Well there's apparently going to be up to 50 characters in the game, so I imagine there'd be a few similar EX abilities.
Terra and Zidane both use Trance as their EX ability, however Terra's increases her STR, MAG and SPD, whereas Zidane's does a thing for his Steal, as well as allow him to dash for much longer and removes debuffs.

For Nael, her EX Ability can just be called 'Bahamut's Favour,' which increases her attack power. When she does it a third time, she transforms (permanent unless KO'd). Increased attack power, Brave Regen and movement (this would make her slightly similar to Kuja's EX instead).

Actually, something else. Lunar Dynamo. It'll still work similarly to the previous idea, but instead it has to actually hit someone. It will either need to be used 1-3 times (depending on how many get hit by it) before you can even transform (and it follows similar rules to FFXIV's. Target must not be too far and not too close). Drains 500 Brave and some HP as well. Changes into Bahamut's Favour after transformation.