hmmm, let me see.
Idea one: An arc sword (Legend's rule), that, if you are at full health, you can, even without ammo, shoot a thing similar to black talon, does way less damage (and also, way faster), but applies a blind effect and does an effect similar to what a tether does to your aim, thus, you give up heavy slot, for a sword that can blind and mess with enemy aim, but, if you take damage before you swing, you get nothing, thus forcing you to use it wisely.

Lore sample: "I saw him, he charged the four armed freaks, blinding lights, he ruined them, those who ran, he chased them, he is real, a undying warrior does protect us, lying in wait. To protect us"

Idea 2: A Solar smg (Burning pride), which uses special ammo, shoots explosive rounds similar to sky burner's oath(yet again, faster), is more accurate, but does less damage the closer you are to the opponent, but more at a moderate distance, then proceeds to fall off in damage, thus making it shred and flinch at a specific distance, uses a rarer ammo, give it a decent scope which shows you the distance of what you are aiming at, thus helping you know the sweet spot.

"Really makes me proud when this beauty explodes one of them"
Idea 3: A kinetic scout rifle (Together), with a unique perk, which increases precision damage for the next shot (or until you reload), for each body shot you make, thus, if you are working with a team, you weaken targets, team mates land killing blows, then, bingo, one shot kill to the face, but, you've got a smaller clip than usual, but let's also put something similar to white nail, land 3 body shots in a row, get 1 bullet added to the clip. let's also give it a unique intrisic perk, Marker rounds, if you are in a fire team, shots mark targets, lowering the damage you deal to them with this weapon, but increase the damage your team mates deal to them.

"Never liked being alone, so, I made this, because, some things, are better together"
Idea 4: A solar linear fusion rifle, (Ruination), has no charge time, has iron sights, no scope, now, this is where things get tricky, for pvp, each elemental kill (with a cooldown between kills to prevent single shot supers from causing problems) gives you one shot, however, you can't pick up heavy ammo from the floor, or from the wall, and but you still drop yours, a headshot is an instat kill like normal, in pve you can still pick up ammo from the ground, and you still have ammo generation on elemental kills, with a shorter cooldown than in pvp.
"They thought I had brought ruin, but the worst had yet to come."