https://gyazo.com/1c0225577ea29367af021ea6d126f1bb
The parts are position always on the first player that joins first.
When player1 says ui the parts are positioned on player1, seems normal but
when player2 says ui the parts are positioned on player1, which is not normal, they should be at player2's position and not player1's position
Script
wave2 = Instance.new("Part")
mesh = Instance.new("SpecialMesh", wave2)
mesh2 = Instance.new("SpecialMesh", wave4)
mesh3 = Instance.new("SpecialMesh", wave5)
mesh4 = Instance.new("SpecialMesh", wave6)
wave = Instance.new("Part")
wave3 = Instance.new("Part")
wave4 = Instance.new("Part")
wave5 = Instance.new("Part")
wave6 = Instance.new("Part")
variable = function(p)
script.Parent.uiactive.Value = true
game.Workspace.ssj.Disabled = true
game.Workspace.ssg.Disabled = true
game.Workspace.ssgss.Disabled = true
game.Workspace.ssgsskkx10.Disabled = true
game.Workspace.kaioken.Disabled = true
game.Workspace.baseform.Disabled = true
script.Parent.particle.ssgssdot.Enabled = false
script.Parent.particle.ssgdot.Enabled = false
mesh2.Parent = wave4
mesh3.Parent = wave5
mesh4.Parent = wave6
wave.Name = "wave"
wave2.Name = "wave2"
wave3.Name = "wave3"
mesh.Name = "mesh"
wave4.Name = "wave4"
wave5.Name = "wave5"
wave6.Name = "wave6"
mesh2.Name = "mesh2"
mesh.MeshId = "http://www.roblox.com/asset/?id=3270017"
mesh2.MeshId = "http://www.roblox.com/asset/?id=3270017"
mesh3.MeshId = "http://www.roblox.com/asset/?id=3270017"
mesh4.MeshId = "http://www.roblox.com/asset/?id=3270017"
mesh.Offset = Vector3.new(0, 0, -80)
wave.Parent = game.Workspace
wave.Size = Vector3.new(0.05, 0.05, 0.05)
wave.CanCollide = false
wave.Anchored = true
wave.Position = p.Character.HumanoidRootPart.Position
wave.Color = Color3.fromRGB(255, 255, 255)
wave.Shape = Enum.PartType.Ball
wave.Material = Enum.Material.Neon
wave2.Parent = game.Workspace
wave2.Size = Vector3.new(0.05, 0.05, 0.05)
wave2.CanCollide = false
wave2.Color = Color3.fromRGB(255, 255, 255)
wave2.Anchored = true
wave2.Position = p.Character.HumanoidRootPart.Position
wave2.Material = Enum.Material.SmoothPlastic
wave2.Orientation = Vector3.new(90, 0, 0)
wave3.Parent = game.Workspace
wave3.Size = Vector3.new(2048, 1, 32)
wave3.CanCollide = false
wave3.Color = Color3.fromRGB(255, 255, 255)
wave3.Anchored = true
wave3.Transparency = -1
wave3.Position = p.Character.HumanoidRootPart.Position
wave3.Material = Enum.Material.Neon
wave3.Shape = Enum.PartType.Cylinder
wave3.Orientation = Vector3.new(0, 0, 90)
wave4.Parent = game.Workspace
wave4.Size = Vector3.new(2, 4, 4)
wave4.CanCollide = false
wave4.Color = Color3.fromRGB(255, 255, 255)
wave4.Anchored = true
wave4.Position = p.Character.HumanoidRootPart.Position
wave4.Material = Enum.Material.Neon
wave4.Shape = Enum.PartType.Cylinder
wave4.Orientation = Vector3.new(90, 0, 0)
wave5.Parent = game.Workspace
wave5.Size = Vector3.new(2, 4, 4)
wave5.CanCollide = false
wave5.Color = Color3.fromRGB(255, 255, 255)
wave5.Anchored = true
wave5.Position = p.Character.HumanoidRootPart.Position
wave5.Material = Enum.Material.Neon
wave5.Shape = Enum.PartType.Cylinder
wave5.Orientation = Vector3.new(90, 0, 0)
wave6.Parent = game.Workspace
wave6.Size = Vector3.new(2, 4, 4)
wave6.CanCollide = false
wave6.Color = Color3.fromRGB(255, 255, 255)
wave6.Anchored = true
wave6.Position = p.Character.HumanoidRootPart.Position
wave6.Material = Enum.Material.Neon
wave6.Shape = Enum.PartType.Cylinder
wave6.Orientation = Vector3.new(90, 0, 0)
script.Parent.Handle.ssgss:Play()
script.Parent.Handle.mui:Play()
for i = 1, 200 do
wave.Size = wave.Size + Vector3.new(4, 4, 4)
mesh.Scale = mesh.Scale + Vector3.new(8, 8, 2)
wave.Transparency = wave.Transparency + 0.01
wave2.Transparency = wave2.Transparency + 0.01
mesh.Scale = mesh.Scale + Vector3.new(1, 1, 0)
wave3.Transparency = wave3.Transparency + 0.01
wave3.Size = wave3.Size + Vector3.new(0, 4, 0)
wave4.Size = wave4.Size + Vector3.new(16, 16, 0)
wave5.Size = wave5.Size + Vector3.new(8, 8, 0)
wave6.Size = wave6.Size + Vector3.new(4, 4, 0)
mesh2.Scale = mesh2.Scale + Vector3.new(16,16,0)
mesh3.Scale = mesh3.Scale + Vector3.new(8,8,0)
mesh4.Scale = mesh4.Scale + Vector3.new(4,4,0)
wave4.Transparency = wave4.Transparency + 0.01
wave5.Transparency = wave5.Transparency + 0.01
wave6.Transparency = wave6.Transparency + 0.01
wait(0.01)
end
wave2:Destroy()
wave:Destroy()
wave3:Destroy()
script.Parent.Handle.Mesh.MeshId = "rbxassetid://865167555"
script.Parent.Handle.muisound:Play()
script.Parent.Handle.ssgssaura.Enabled = false
script.Parent.Handle.ssgaura.Enabled = false
script.Parent.Handle.ssjaura.Enabled = false
script.Parent.Handle.kx10aura.Enabled = false
script.Parent.Parent.Torso.ui1.Enabled = true
script.Parent.Parent.Torso.ui2.Enabled = true
script.Parent.Parent.Head.ui1.Enabled = true
script.Parent.Parent.Head.ui2.Enabled = true
script.Parent.Parent["Left Leg"].ui1.Enabled = true
script.Parent.Parent["Left Leg"].ui2.Enabled = true
script.Parent.Parent["Right Leg"].ui1.Enabled = true
script.Parent.Parent["Right Leg"].ui2.Enabled = true
script.Parent.Parent["Left Arm"].ui1.Enabled = true
script.Parent.Parent["Left Arm"].ui2.Enabled = true
script.Parent.Parent["Right Arm"].ui2.Enabled = true
script.Parent.Parent["Right Arm"].ui2.Enabled = true
script.Parent.Handle.Mesh.Scale = Vector3.new(6, 6, 7.2)
script.Parent.Handle.ssj:Stop()
script.Parent.Handle.ssg:Stop()
script.Disabled = true
game.Workspace.ssj.Disabled = false
game.Workspace.ssg.Disabled = false
game.Workspace.ssgss.Disabled = false
game.Workspace.ssgsskkx10.Disabled = false
game.Workspace.kaioken.Disabled = false
game.Workspace.baseform.Disabled = false
end
game.Players.PlayerAdded:Connect(variable)
for _, player in pairs(game.Players:GetPlayers()) do
variable(player)
end

3 comments
You might want to invest in a scripter. Or, you could learn how to use for loops.
Also, if your code looks like this, you should either rework the structure of your code or your game objects.
To poor to invest in a scripter.