Grisyn

How does its damage calculation work? Total output = (base damage + serration + 1000 (passive) * elementals? Or total output + 1000 (passive)?

As much as the title says, despite clearly being a channeled ability is not treated by incarnon weapons as such. Same applies to Ash's Blade Storm.

Although the riven affects the reload time, looks totes (after testing in the Elite Sancturay, still (in the simulacrum the problem does not appear)) like Energized Munitions are the issue here.

The Ash with Energized Munitions was used, and the mission was Elite Sanctuary Onslaught. Rauta had a riven (Acri-satisus (amogus)) with the following stats: +54.7% Slash; +59.1% Multishot; +46% Critical damage; -16.9% Reload Speed; After a few magazines, the weapon reload time ramps up to around 30 seconds, and then even more. I was mainly shooting while aiming. Here's a video depicting the issue.