I stumbled over Omni's livestream by mistake and it seems like he did something similar to this.
Here! (Round the 30min mark-ish)
What he uses is a Massive patch with all three oscillators running saw wave forms and an envelope to alter the pitch of all three (I think, I'm no massive expert).
I've noticed that routing the filter envelope to one or more of your oscillators on most synths and playing around with the decay will yield a kind of "laser-gun" sound. Not sure if that's what's going on here, it's probably more complex than that, but hey it's a start.