(See the best response by Neimo.)

Problem description:

i have this tech in my game that in code i have it change the players icon to an explosion, and to return them back to normal i put it back to null, but i found out it doesnt work b/c their invisible, so i need a way to put it so they change back. also i dont think posting the code matters so i didnt
Instead of changing icon to null, change it to a specific icon. You can prolly store the icon (or icon state) in a variable to keep it simple. If it's a game where it's not important to save characters, you can use the initial() proc to cut a few lines.
Best response
Or you can just flick the icon you want to animate.

//object being the player
flick('icon file.dmi', object)
Well its a dbz game so seeing your char matters and the flick thing didnt work
In response to Nourn
It probably doesn't work because you have it set to a certain icon_state, try using the icon() proc.

flick(icon(icon = 'file.dmi', icon_state = "state"), object)
oh wow, i just thought of an easy way to do it, i could add the icon to every race and put it as in icon state, but is there any way to change the layer of it so it can be on top, b/c if they are wearing icons they'll still have them when the explosion icon is on them.