The rift just seems to cast 10 bolts at the moment. I'm trying it through arena skirmishes on the PTR fyi and tracking the spell details through Recount.
ATM the skirmish buff will max out your artifact weapon while in the arena, so all you need to do is the spec specific questline to unlock the new traits (triggered by having enough AP in the weapon to unlock at least the 5% damage trait on live).