As detailed onBungie.net, the new subclass lets you combine certain class abilities and damage types.
The Weaver shoots waves that suck in players, and the Grim is a bat with a gun.
Commendable Sinister Six vibes.

The Final Shape launches 4th June.
It’s prefaced by an on-going event Into the Light, which started yesterday and runs till 3rd June.
The recentGhostbusters crossovermay reflect a certain urgency about driving up revenues.
