I found a glitch. if you create a custom item, and name it the same name as an in-game item, when spawning the in-game item it will instead spawn your custom item. please + so 0rava can see!
Unfortunately that's a lot more complex than it may sound like. All lasers/rays/beams/etc use raycasting to detect collisions, which would have to be intercepted and redirected, which is no simple feat.
Try the Incendiary.