BC required: 32 Max BC generated: 35 (1 BC/hit) 35 combo massive Light attack on all foes (damage relative to remaining HP)[1500-2800%], enormously boosts critical damage [300%] for 3 turns, enormously boosts Spark damage [300%] for 3 turns, enormously boosts Atk [300%] for 3 turns, enormously boosts critical hit rate [60%] for 3 turns & high probability [85%] of activating BB/SBB/UBB twice for 1 turn

Now youre thinking "Shaun youre retarded it doesnt give back 50% OD gauge so you cant infinite UBB

But realise this

It has a 85% chance of double activating bb/sbb/ubb

That means that For example, Benimaru can instafill 20% OD gauge instead of 10% at a 85% chance since it double procs

... Im pretty sure its only one turn or else you could Arthur UBB > Shion UBB and Shion UBB fills 50% OD gauge twice and youd have infinite Shion Arthur UBB

Anyway one step closer to nuke Frontier. Maybe FH Viable, where you can UBB every stage without guarding with Like One Arthur Five perfect sparking Shions or something?

Edit: especially since od fill rate resets between fh stages and you get instafill normal fill, you dont need all five to double bb