Comic Find !! Uncanny X-Men #221 Title: Uncanny X-Men Issue: #221 Volume: #1 Publisher Marvel Comics Date: September 10, 1987 Written By: Chris Claremont Pencils: Marc Silvestri Inks: Dan Green Colors: Glynis Oliver Letterer: Tom Orzechowski Cover by: Marc Silvestri Key Issue: First appearance of Mister Sinister. here is a nice key issue. the first appearance of Mr. Sinister.