Getting this morph to work?

Ok so I have this script that basically makes this huge model appear behind you but I keep running into a couple problems. Firstly the model appears where your torso was but you get launched 200-300 studs in a random position, also you occasionaly get pushed under the map and once the Welds get delted you fall to your death, How can I fix this?

Side Note:I know this script is very sloppy, I was in that try anything to get this to work stage

wait(2)
local bin = script.Parent
local Player = game.Players.LocalPlayer
local mouse = Player:GetMouse()
local c = Player.Character

enabled = true


function onButton1Down(mouse)
    if not enabled then return end
    local player = game.Players.LocalPlayer
    if player == true then return end
    print("trigger")
    -- find the best cf

enabled = false
game:GetService("Chat"):Chat(c.Head, "Saiken!!!")
C=c.Torso.CFrame
wait(0.001)
local B1 = script.Parent.Saiken:Clone()
local B2 = B1:GetChildren()
B1.Parent = game.Workspace




B1.Name = ("6 Tail")
B1.PrimaryPart = B1.Chest
B1:SetPrimaryPartCFrame(C*CFrame.new(0, 0, 30))
for i = 1, #B2 do
game.Players.LocalPlayer.Character.HumanoidRootPart.Anchored = true   
W1 = Instance.new("Weld")
   W1.Parent = B2[i]
   W1.Part0 = game.Players.LocalPlayer.Character.HumanoidRootPart
   W1.Part1 = B2[i]
   W1.C0 = C*B2[i].CFrame

game.Players.LocalPlayer.Character.HumanoidRootPart.Anchored = false
game:GetService("Debris"):AddItem(W1, 19.9)
end

wait(1)

game.Players.LocalPlayer.Character.Humanoid.WalkSpeed = 100
game:GetService("Debris"):AddItem(B1, 20)
wait(25)
game.Players.LocalPlayer.Character.Humanoid.WalkSpeed = 16

enabled = true
end

function onSelected(mouse)
    print("select")
    mouse.Icon = "rbxasset://textures\\GunCursor.png"
    mouse.Button1Down:connect(function() onButton1Down(mouse) end)
end

bin.Selected:connect(onSelected)