I've made a block spawn in, but why can't I make it disappear?

I think your issue is with the end functions.

local F1 = game.ServerStorage.Skill3:WaitForChild("1Fire")
local F1C = F1:Clone()
F1C.CFrame = Player.HumanoidRootPart.CFrame * CFrame.new(0,-2,0)
F1C.Parent = workspace
local Debounce = false
Touch = F1C.Touched:Connect(function(hit)
if Debounce == true then return end
     Debounce = true
     if hit.Parent:FindFirstChild("Humanoid") then
             if hit.Parent.Name ~= player.name then
                    hit.Parent.Humanoid:TakeDamage(60)
                    wait (0.4)
                    F1C:Destroy()
              end
       end
end

You put a close bracket on first end, but there aren’t any functions to close. Instead, you have three if statements to close.