Return of Reckoning

Ha e to agree, it's a 100% bonus proc. The ability itself doesn't require a mutation and the proc shouldn't be included for PB. It's also top two moast bang for buck tactics in the game together with Runefang and doesn't need to be better in anyway.

flail doesnt requires mutation so PB doesnt works with it.

As has been said, the proc is not an ability. Seems like it's working as intended.