use the paint bucket tool to make the background #000 black
draw the appropriate sigil using a brush that has some grain to it. here are my settings.
remember, you want it to look amateurishly assembled as though it were done in a hurry during cloud cover of a full moon using improvised materials.
activate the sigil using a luminosity layer and light color of your choosing. im partial to red. play with the layer opacity until its as ominous as you prefer
use the move tool to retrieve donald from the sigil
hope this helps!