In looking for a way of conveying motion, and also to spruce up the model I was planning on adding some banners to the Sonic Lances. I was thinking about scratch building them, but then I saw some bits in my bits box that would do the trick.
These banners are leftovers from a High Elf dragon. They seem the right scale when compared to the Revenant.
Here is a picture of one tacked onto a sonic lance temporarily.