[quote=@Forsythe]
Problem: Dark energy does not interact with matter, so what's the point of making weapons with it? XD And antimatter and RKVs are at the very least confirmed to exist, so putting those in the same bag as DE is not really correct.
[/quote]

Please correct me if I am wrong, [@TheMusketMan], but given that the first picture in the application is a Combine clamp, I'm going to guess it is going for the Half Life Pulse Rifle/AR2 style of weapon. In which case, it isnt strictly speaking firing Dark Energy, it fires super heated exotic energy particles (for convieniance, termed 'Dark energy plasma') which is drawn from self replicating reactions within a dark energy core and stored within Pulse Rifle Energy Cells which the rifle uses as ammunition and therefore the rounds do interact with matter. So in other words, super plasma rifle.