Divinity//Moonlight because Arceus is God [literally] and Umbreon is my favorite Eeveelution.
And now for the first theme idea in this thread: Egyptian Aura!
DESUkan and Lucario! Desukan is obviously, a sarcophagus, and Lucario resembles Anubis, the Egyptian god of the...Underworld? Death? Either way, it works. Color would probably be yellow due to sand and the pyramids seen as yellow.
Probably the best artwork to use for both. If you want, I could look for other images.