Creation

Mr. Smile first appeared in Dr. Strange #5 by Mark Waid and Kevin Walker.

Major Story Arcs

Strange's Forge

Mr. Sulk and Mr. Smile were working for Madame Masque, when she learned how to break into Doctor Strange's arcana forge on Nidavellir. Strange tracked the two demons down by the energy signature of their new weapons. Smile had the Mallet of Entropy, which caused the atomic structure of anything it hits to destabilize

Using the opposite nature of Sulk and Smile's weapons, Strange was able to cause them to destroy each other and then sent the two demons to a dungeon dimension.

Escape

Sulk and Smile were able to escape the dungeon dimension, but it came with a price. They had to replace themselves with human souls. They were caught dragging humans to a dungeon dimension portal by the Midnight Mission. Hunter's Moon performed an exorcism, which sent them right back.