Third-Person Omniscient

Not much to note here, since third-person omniscient is the go-to method for movie narrative. It's smooth, it doesn't ruffle any feathers and it gets us the information we need without making us aware of what it's doing. When you have this many plot threats flying together, there's no need to get cute.

Whedon sticks with the basics and doesn't let the technique get in the way of the story he's telling. There's seven main heroes we have to follow, and that's quite a feat in and of itself. No need to get cute with the narrative.