The Uncanny X-Men #221 comic book is a vintage collectible from the US Comics tradition, graded 8.5 Very Fine+ by Certified Guaranty Company (CGC). This single issue features the first full appearance of Mr. Sinister and showcases the superhero team, X-Men, in a story titled "Death by Drowning." Written by Chris Claremont and illustrated by Marc Silvestri, this 1987 publication is a part of the Marvel (MCU) universe and is considered a valuable addition to any comic book collection for general audience enjoyment.