Ok I already have it working, but when a player drops the tool, the script breaks because the instance changes, which is, really annoying, I have no clue how to make a multiplayer solution, and it's been driving me crazy for like a week now. I've come up with many things that just do not work.
print("SUC")
function equipped()
local humanoid = script.Parent.Parent:WaitForChild("Humanoid")
humanoid.MaxSlopeAngle = 200
end
script.Parent.Unequipped:Connect(function()
local human = script.Parent.Parent.Parent.Name
local hum = game.Workspace[human].Humanoid
hum.MaxSlopeAngle = 50
end)
script.Parent.Equipped:Connect(equipped)
Like I said it works, but when the tool is dropped it just breaks from being in the workspace instead of making the maxslopeangle 50.

1 comment
This is very useful information, I was using a normal script cause I was skeptical that a local script would be able to edit the humanoid, but then I realized that, the server isn't "seeing" but the client is so it's like the exact same as someone using a script injector client thing to let the be able to fly. Thanks!