Change Sprite1, center it, and watch the magic happen. The backdrop gives a hint to who the characters in Sprite 1 are. It's best to have something to do while waiting for it to get to the Sprite or make the Sprite bigger (Yes, it's THAT slow). I also added music(It's FNF, so sorry if it's not enjoyable) Because I sped it up from 1x per move to 10x per move, it's a bit less accurate. DO NOT USE A HIDE BLOCK ON SPRITE1, THAT WILL JUST MAKE IT NOT WORK. The grey and black do not mean anything different. Also, make sure the image has a transparent background. Do not change sprite/costume while it's going.
There is a better one on my alt, @The4thaccount