Aphelios s crazy Severum (main hand) + Crescendum (off hand) combo

So basically our edgy boy has a crazy ass combo that uses the active Q for Severum to stack Crescendum in offhand to absurd levels of damage. Once you exhaust Severum s ammo you swap Crescendum to main hand and dump all of your stacks while refreshing them in combat until Crescendum runs out. I feel like this isnt super busted, its kinda like Kalista stacking 1000 spears on gromp and q ing someone to oneshot them.