i had some ideas for weapons but i dont really do add-on dev anymore so i think someone else should make it
drifter rifle + tomohawk
basically a dual wield weapon where the your right hand holds a super powerful magnum / lever rifle and the left hand holds a tomohawk or other melee weapon. the lever rifle has four ammo shots that you can burn thru pretty quickly. once you run out of ammo you cant fire anymore, but using the tomahawk (left click) will basically allow you to do a powerful melee strike that allows you to lunge in on close enemies in your vision (like the halo energy sword). every melee strike rewards you one bullet for your rifle so you can resume firing. also the tomahawk can deflect bullets if you time your slice really well
the idea is basically a duo weapon where you alternate between high risk precision long range shots from your rifle and wanton slicing with your tomahawk
charge beam
basically the polar star from cave story. firing rapidly fires tiny bullets that do almost no damage but holding left click charges the gun for a higher damage shot. the max charge should be somewhere at like 3 seconds and if you exceed that amount it autofires
medislaughter
basically a splash damage missile launcher that is kinda weak. all damage you do against enemies raises a little power meter, and every shot you shoot near a teammate distributes the power meter as healed health. so like, if you shoot a couple enemies and deal a total of 100 damage, you can now heal your teammates by shooting next to them up to 100 (maybe 75?) points of health back. it makes for a nonboring medical weapon where you can alternate between dishing out damage and healing your teammates and stuff