How to make a jumpscare with some other effects and death screen?

You want it to slide from the bottom of the screen where it isn't visible, up to the center? Easy enough! We use something called Tween to do this. I had no idea what it is, when I was at your level too! But it's very easy and good.

IMPORTANT!

Make the original frame or imageframe position {0,0,-1,0} or this will not work.

Here's how to tween, this seems more of a request than a question, but I like to help, because then you learn for next time.

Let's start with tweening

--LocalScript!

local player = game.Players.LocalPlayer

function Tween()
    local YourGui = player.PlayerGui.GUINAMEHERE! -- change GUINAMEHERE! to what your GUI is         called.
    local YourFrame = YourGui.YOURFRAMENAMEHERE -- [[change YOURFRAMENAMEHERE to the name    of your frame in your GUI--]]

    YourFrame:TweenPosition(UDim2.new(0,    0,  0,  0))
end

Now, we must link the function to make it play, so let's do that when the player dies.

player.CharacterAdded:connect(function(char)
     char.Humanoid.Died:connect(function()
        Tween()
     end)
end)

Hope I helped, good day!