Why is the "kiblast" doing more than 5 damage?

Tool = script.Parent Player = Tool.Parent.Parent Character = Player.Character Humanoid = Character.Humanoid root = Character.HumanoidRootPart Mouse = Player:GetMouse()

Tool.RemoteEvent.OnServerEvent:Connect(function(Player, mouseHit)

root.CFrame = CFrame.new(root.Position,root.Position + Vector3.new(mouseHit.lookVector.x, 0, mouseHit.lookVector.z)) --[[ 1st argument is position second argument is direction ( where it is
	is and where its going to look at]]
local kiblast = Tool.Handle:clone()
game.Debris:AddItem(kiblast, 2)
kiblast.CFrame = Humanoid.Parent.RightHand.CFrame
local v = Instance.new("BodyVelocity")
v.Parent = kiblast
v.velocity = mouseHit.lookVector * 90
v.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
kiblast.CanCollide = false
kiblast.Parent = game.Workspace
kiblast.Transparency = 0
kiblast.Touched:Connect(function(hit)
	
	local hum = hit.Parent:findFirstChild("Humanoid")
	if hum and hum ~= Humanoid then
		local explosion = Instance.new("Part")
		local Torso = hum.Torso
		explosion.Parent = game.Workspace
		explosion.Shape = "Ball"
		explosion.BrickColor = BrickColor.new("New Yeller")
		explosion.Material = "Neon"
		explosion.Size = Vector3.new(15, 15,15)
		explosion.CanCollide = false
		explosion.Position = Torso.Position
		explosion.Anchored = true
	for i = 0, 1, 0.02 do
	wait(0.01)
	explosion.Transparency = i
	 end
			hum:TakeDamage(5)
						game.Debris:AddItem(explosion, .0000000000000000001)
	elseif hit.Anchored and hit.CanCollide == true then
		
			for i = 1,10 do
			local part = kiblast:clone()
			part.Size = Vector3.new(0.5 , .5, .5)
			part.CFrame = kiblast.CFrame
			part.Parent = game.Workspace
			part.BodyVelocity.Velocity = Vector3.new(math.random(-15,15), math.random(-15,15), math.random(-15,15)) * 5  --[[
				without the times 50 it goes at a random speed i think
			--]]
		    game.Debris:AddItem(part, 1)
		

		
	end
	end
end)

end)

You need to add a debounce for your Touched function.

You made a few mistakes which I corrected. I haven't taken the time to test this script, but hopefully you can learn stuff from it.

Hope this works, any questions let me know in the comments.

local Tool = script.Parent

local Player = Tool.Parent.Parent:IsA("Player") and Tool.Parent.Parent or game.Players:GetPlayerFromCharacter(Tool.Parent)
local Character = Player.Character or Player.CharacterAdded:Wait() -- wait for character to load in if it hadn't already
local Humanoid = Character:FindFirstChildWhichIsA("Humanoid") -- humanoid's name could change for some reason, let's just make sure we get it
local root = Character.PrimaryPart -- the primary part for the character is the HumRootPart
local Mouse = Player:GetMouse() -- this is fine

Tool.RemoteEvent.OnServerEvent:Connect(function(Player, mouseHit)
root.CFrame = CFrame.new(root.Position,root.Position + Vector3.new(mouseHit.lookVector.x, 0, mouseHit.lookVector.z)) --[[ 1st argument is position second argument is direction ( where it is
    is and where its going to look at]]
local kiblast = Tool.Handle:Clone()
game.Debris:AddItem(kiblast, 2)
kiblast.CFrame = Humanoid.Parent.RightHand.CFrame
local v = Instance.new("BodyVelocity")
v.Parent = kiblast
v.velocity = mouseHit.lookVector * 90
v.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
kiblast.CanCollide = false
kiblast.Parent = game.Workspace
kiblast.Transparency = 0
local connection -- make this accessible in the future by defining the variable here
connection = kiblast.Touched:Connect(function(hit)
    connection:Disconnect() -- get rid of future touched connections
    local hum = hit.Parent:FindFirstChild("Humanoid")
    if (hum and hum ~= Humanoid) then
        local explosion = Instance.new("Part")
        local Torso = hum.Parent:FindFirstChild("Torso") or hum.Parent:FindFirstChild("UpperTorso") -- Rig compatibility
	--[[
		Remember, the Torso is a part of the player's character, not his humanoid
		This means we need to get it from the character aka the humanoid's parent.
	--]]
        explosion.Parent = game.Workspace
        explosion.Shape = "Ball"
        explosion.BrickColor = BrickColor.new("New Yeller")
        explosion.Material = "Neon"
        explosion.Size = Vector3.new(15, 15,15)
        explosion.CanCollide = false
        explosion.Position = Torso.Position
        explosion.Anchored = true
    for i = 0, 1, 0.02 do
    wait(0.01)
    explosion.Transparency = i
     end
            hum:TakeDamage(5)
                        game.Debris:AddItem(explosion, 1e-8) -- much neater way of writing it
    elseif hit.Anchored and hit.CanCollide == true then

            for i = 1,10 do
            local part = kiblast:Clone()
            part.Size = Vector3.new(0.5 , .5, .5)
            part.CFrame = kiblast.CFrame
            part.Parent = workspace
            part.BodyVelocity.Velocity = Vector3.new(math.random(-15,15), math.random(-15,15), math.random(-15,15)) * 5  --[[
                without the times 50 it goes at a random speed i think
            --]]
            game.Debris:AddItem(part, 1)



    end
    end
end)

If this answers your question, please be sure to accept my answer so the helpers know this article is closed.

Kind regards, Rod455

add a debounce