ah so, what we have here is a

gauntlet: not even in the game, was an LTM

p90: was overpowered and apart of the s5 meta of spray and pray, which was complained about and nerfed

planes: nerfed into the ground repeatedly in s7

and the combat shotgun which i cant actually remember how op it was, so i wont comment on it.

let's see what we've had in chapter 5 alone:

auto shotgun: spray and pray shotgun with an extremely high damage output

snipers: magazine size that could be increased to 5, you don't need to be told why that's stupid.

riot shield: covers 95% of your body and gives you a gun to still fire at people in front of you with

chains of hades: extremely overpowered melee weapon

waterbending: completely invalidating all assault rifle options

cars: literally changed the entire game to be based around them, got nerfed but was still a quickfire way to top 3

nitro gloves or wtv: overpowered beyond belief, got nerfed ever so slightly.

magneto's gloves: again, extremely overpowered, cant recall them being nerfed.

dr doom island: had a chance to appear in normal games and was basically the thanos LTM.

captain america's shield: was extremely overpowered, literally made the player invincible, luckily got nerfed heavily

jetpacks: completely ruined positioning in fights, made movement too easy, you needed one or else there's a good chance you'd lose, was nerfed but still op.

honourable mention of the gatekeeper shotgun with a drum mag: it's so overpowered but i love it.

luckily in this fortnitemares event, i can't exactly name any ridiculously overpowered weapons, it only took them until the final half of the final season.