Why wont this Kill Leaderboard work?

Im trying to make a leaderboard that keeps up with the number of zombies you have killed however i cant get it to work.

The leaderboard:

game.Players.PlayerAdded:connect(function(player)
    local leaderstats = Instance.new("IntValue", player)
    leaderstats.Name = "leaderstats"

    local Kills = Instance.new("IntValue", leaderstats)
    Kills.Name = "Kills"
    Kills.Value = 0

    local deaths = Instance.new("IntValue", leaderstats)
    deaths.Name = "Deaths"
    deaths.Value = 0

    local experience = Instance.new("IntValue", leaderstats)
    experience.Name = "Exp"
    experience.Value = 0

    local rank = Instance.new("IntValue", leaderstats)
    rank.Name = "Rank"
    rank.Value = 1

    local Money = Instance.new("IntValue", leaderstats)
    Money.Name = "Money"
    Money.Value = 0

end)

The Script in the zombie:

local Humanoid = script.Parent.Zombie 
function Killed() 
local tag = Humanoid:findFirstChild("creator") 
if tag ~= nil then 
if tag.Value ~= nil then 
local Leaderstats = tag.Value:findFirstChild("leaderstats") 
if Leaderstats ~= nil then 
Leaderstats.Kills.Value = Leaderstats.Kills.Value + 1
wait(0.1) 
script:remove() 
end 
end 
end 
end 
Humanoid.Died:connect(Killed) 

The three scripts in the weapon:

-- Local variables
local tool = script.Parent
local currentAmmo = tool.Configurations.ClipSize.Value
local canFire = true
local reloading = false
local fireSound = tool.FireSound

-- Configurable variables
local attackCooldown = tool.Configurations.AttackCooldown.Value
local range = tool.Configurations.Range.Value
local damage = tool.Configurations.Damage.Value
local reloadTime = tool.Configurations.ReloadTime.Value
local clipSize = tool.Configurations.ClipSize.Value

-- Setup Remote Events
local function createEvent(eventName)
    local event = game.ReplicatedStorage:FindFirstChild(eventName)
    if not event then
        event = Instance.new("RemoteEvent", game.ReplicatedStorage)
        event.Name = eventName
    end
    return event
end
local updateEvent = createEvent("ROBLOX_PistolUpdateEvent")
local equipEvent = createEvent("ROBLOX_PistolEquipEvent")
local unequipEvent = createEvent("ROBLOX_PistolUnequipEvent")
local fireEvent = createEvent("ROBLOX_PistolFireEvent")
local reloadEvent = createEvent("ROBLOX_PistolReloadEvent")

-- Add tracer decal to server storage if it isn't already there
if not game.ServerStorage:FindFirstChild("ROBLOX_PistolTracerDecal") then
    tool.ROBLOX_PistolTracerDecal:Clone().Parent = game.ServerStorage
end

-- Bind function to update event. Used to update player's orientation if FilteringEnabled
-- is true (otherwise the rotation would not replicate from the rotating player)
updateEvent.OnServerEvent:connect(function(player, neckC0, rshoulderC0)
    local character = player.Character
    character.Torso.Neck.C0 = neckC0
    character.Torso:FindFirstChild("Right Shoulder").C0 = rshoulderC0
end)

-- Bind functions to when player equips/unequips the tool. Right now just need to turn on and
-- off AutoRotate
equipEvent.OnServerEvent:connect(function(player)
    player.Character.Humanoid.AutoRotate = false
end)
unequipEvent.OnServerEvent:connect(function(player)
    player.Character.Humanoid.AutoRotate = true
end)

-- Creates "bullet". No projectile motion is actually used. Pistol raytraces to target and creates
-- a tracer trail to the target. Fading trail gives illusion of motion.
local function createBullet(target)
    -- Get actual handle position. Want to offset from the center of the handle as the bullet comes
    -- from the barrel of the gun
    local handlePos = tool.Handle.CFrame + tool.Handle.CFrame:vectorToWorldSpace(Vector3.new(0,0,.3))
    local toTarget = handlePos:vectorToWorldSpace(Vector3.new(0,1,0)) * 200
    local torsoLook = (tool.Parent:FindFirstChild("Torso").CFrame.lookVector * Vector3.new(1,0,1)).unit
    local toTargetAngle = (toTarget * Vector3.new(1,0,1)).unit
    local angle = math.acos(torsoLook:Dot(toTargetAngle))

    -- Checks angle from where the character is facing to the orientation of the pistol. If the angle
    -- is less than 90 degress then we shoot to where the mouse is pointing (helps accuracy). Otherwise
    -- the gun is assumed at the edge of its rotation and just shoots straight.
    if math.deg(angle) < 90 then
        toTarget = target - tool.Handle.Position
        if toTarget.magnitude > range then
            toTarget = toTarget.unit * range
        end
        toTarget = toTarget * 1.1
    end

    -- Shoot ray and check if humanoid was hit. If so, it should take damage
    local ray = Ray.new(handlePos.p, toTarget)
    local part, position = game.Workspace:FindPartOnRay(ray, tool.Parent)
    if part and part.Parent and part.Parent:FindFirstChild("Zombie") then
        part.Parent:FindFirstChild("Zombie"):TakeDamage(damage)
    end 

    if position then
        toTarget = position - handlePos.p
    end

    -- Create tracer trail. Trail is made of thin parts 2 studs long. Fades each segment
    -- starting with closest tracer to the tool.
    local bulletTrail = Instance.new("Model", game.Workspace)
    local trailTable = {}
    -- Fetch decal from server storage
    local decal = game.ServerStorage.ROBLOX_PistolTracerDecal
    for i = 0, toTarget.magnitude/2, 1 do
        local trailSegment = Instance.new("Part", bulletTrail)
        trailSegment.CanCollide = false
        trailSegment.Anchored = true
        trailSegment.FormFactor = Enum.FormFactor.Custom
        trailSegment.Size = Vector3.new(.1,.1,2)
        trailSegment.BrickColor = BrickColor.White()
        trailSegment.CFrame = CFrame.new(handlePos.p + (toTarget.unit * 2 * (i + .5)), handlePos.p)
        trailSegment.Transparency = 1

        -- Add point light to tracer for a little illumination
        local light = Instance.new("PointLight", trailSegment)  
        light.Range = 3

        -- Add decal to faces of the part
        local function addDecal(face)
            local decalClone = decal:Clone()
            decalClone.Parent = trailSegment
            decalClone.Face = face
        end     

        addDecal(Enum.NormalId.Top)
        addDecal(Enum.NormalId.Bottom)
        addDecal(Enum.NormalId.Left)
        addDecal(Enum.NormalId.Right)

        -- Add segment to all of the tracers
        table.insert(trailTable, trailSegment)
    end

    -- Coroutine thread to fade each trail segment. Put in coroutine so it does not
    -- block the rest of the pistol's script
    local fadeThread = coroutine.create(function()
        local count = 1
        local ended = false
        -- Keep looping until end condition is met
        while not ended do
            -- Assume end condition is met. Easier to switch it off later if we need to
            -- keep looping
            ended = true
            -- Loop through every part in the trail
            for index, part in pairs(trailTable) do
                if index <= count then
                    local shouldDestroy = false
                    for _, face in pairs(part:GetChildren()) do

                        if face:IsA("Decal") then
                            -- Increase decal transparencies and use this to determine if
                            -- segment has completely faded
                            face.Transparency = face.Transparency + .05
                            if face.Transparency < 1 then
                                ended = false
                            else
                                shouldDestroy = true
                            end
                        else
                            -- Dim the point light
                            face.Brightness = face.Brightness - .1
                        end
                    end         
                    -- If segment is completely faded then clean it up
                    if shouldDestroy then
                        table.remove(trailTable, index)
                        part:Destroy()
                    end     
                end
            end
            count = count + 1
            wait()
        end
        bulletTrail:Destroy()
    end)    
    coroutine.resume(fadeThread)    
end

-- Function to bind to reload event
local function reload()
    if not reloading then
        tool.ReloadSound:Play()
        reloading = true
        canFire = false
        wait(reloadTime)
        currentAmmo = clipSize
        canFire = true
        reloading = false
    end
end

reloadEvent.OnServerEvent:connect(reload)

-- Bind function to fire event
fireEvent.OnServerEvent:connect(function(player, target)
    if tool.Parent == player.Character then
        -- If tool has enough shots then fires. Otherwise reloads.
        if currentAmmo <= 0 then
            return reload()
        end
        if canFire then
            canFire = false
            currentAmmo = currentAmmo - 1
            fireSound:Play()
            createBullet(target)
            delay(attackCooldown, function()
                canFire = true
            end)
        end
    end
end)