Graphical anomaly on PC.
Only ever saw it once as Marquis, running on an AMD R9 390 graphics card, saved using Steams in-game screenshots (f12).
You can see the imgur album here of the issue: God Rays. Tried to capture from multiple angles. Looks like someone may have done some kind of effect behind it and then it stuck?
MatchID is in one of the screenshots on that album.
I never witnessed anything happen, but the timestamp seeing the effect is: