Found a new possible Rouga b&b. Works anywhere, gauge-less/boost-less, 3k-ish damage. Landed it on all the current characters.
9C, 2A, 2B, 2C, 214A, 214B, 5B, 214A, 214B, 5B, 5C, 623A.
The first 214A/B must be done as fast as possible, but the second one must be delayed between the A and B to combo correctly. Not going to lie, for me I only can land it 50/50, seems like a tight link to land a B after the 214B. Can only do two reps, because the 3rd bounce will make them un-hittable.
He might have a stronger corner variation, doing
9C, 5A, 5B, 5C, 214A, j.214A, 5B, 214A, 214B, 5B, 214A, 214B, 5B, 5C, 623A. You use the jump-cancel from a 214A to go into a TK'ed j.214A, and since the high bounce doesn't count as one of your bounces (tested real quick by doing just 5A, 214B x2 after the TK'ed dive, then did B, C, 623A), this may be possible. I haven't done this combo in full though, so I dunno if it works yet.
EDIT: Seems the other variation does less damage, and hard as hell to combo off a jump-in. Flashy I guess, due to all the rekka reps you do lol.