It's possible to make as big of an impact by using sound and not a visual.
"The skies have parted and Olympus answers with a gift. Go NOW!"
You basically have a voice prompt with a great sound effect of the weapon appearing.
If you're playing without sound or you're deaf then it makes it a bit more tricky. This is why the rumble feature helps for something like this.
I think that one of the many things the GoW franchise has been known for is its visuals. To not incorporate something visual seems kind of a letdown to me. No disrespect intended; this is a good suggestion nevertheless.
As you can probably tell... I'm just pro-spear cinematic