Fusion, but not fusion.

[Omni]

It doesn't matter too much as she's only an NPC but regardless, it'd only need fusion (which makes a new form with all the stats and powers/moves of both). That's because in either case, the actual benefits aren't changing, she's just enabling different moves she already has. If you wanted the benefits to change, she'd want alternate forms, so that maybe fusing in her chestplate form gave more of a DEF boost, the wristband gave a TEC boost or what-have-yeh.