Why does it work fine until I add "wait"?

color = script.Parent.BrickColor 
debounce = false

script.Parent.Touched:connect(function(part)
    local h = part.Parent:FindFirstChild("Humanoid")
    if h and (h.WalkSpeed == 3) and (not debounce) then
        h:TakeDamage(0)

elseif h and (not debounce) then
        debounce = true
        h:TakeDamage(2)

local function r()
    return math.random(0.1, 0.5) 
end

local BodyParts = {h.Parent["Right Arm"], h.Parent["Left Arm"], h.Parent.Torso, h.Parent["Left Leg"], h.Parent["Right Leg"]}
local BodyPart  = BodyParts[math.random(1, 5)]

local Shard            = Instance.new("Part")
local Crystal          = Instance.new("SpecialMesh")
Crystal.MeshId         = "http://www.roblox.com/Asset/?id=9756362"
Crystal.Parent         = Shard
Crystal.Scale          = Vector3.new(0.5, 0.25, 3)
Shard.Parent           = BodyPart
Shard.CFrame           = BodyPart.CFrame * CFrame.Angles(0, 0, 0)
Shard.BrickColor       = color
Shard.CanCollide       = false

local w  = Instance.new("Weld")

w.Part0  = Shard
w.Part1  = BodyPart
w.C0     = CFrame.new(0, 0, 0) * CFrame.Angles(r(), r(), r()) 
w.Parent = Shard


wait(3) -- Problem1
for i = 1, 10 do

Shard.Transparency = Shard.Transparency + 0.2
wait(0.1)
end 

wait(5) -- Problem2
Shard:Destroy() 
end
    end)


Shot = script.Parent 

wait(1)
Shot:Destroy()

Everything works fine until I add the wait() . Please help.