Have a pretty cool sfx idea. You can find it from the XGRA game.

It's the "Deathstrike selected" voiceline. when the strike hits the bike the explosion sound is cool too. would work for like halo's charge rifle where there's a wind up time

https://www.youtube.com/watch?v=q_ZWjJF9LZo&t=354s

at about 5:14 you can barely hear it. You'd have to play the game to get the sfx by turning the music off or something. Or maybe someone posted the files to thecuttingroomfloor I'd make a mod myself but not familiar with gmod/source and don't have the time to learn. thanks