SPOILER WARNING: The following article contains minor spoilers for "Uncanny X-Men" #11, in stores now.
Modern comics writers play a long game, and not many do it better than Brian Michael Bendis. Looking back though his work at Marvel, one can find a number of teases seeded for then-future events. The writer included hints of the Skrull invasion during his "Avengers: Disassembled" arc, going up through "House of M," "Civil War" and "Secret War," and the recently concluded "Age of Ultron" was teased years in advance in his "Avengers" titles. And with "Uncanny X-Men," it seems that the writer remains a dedicated long game player, as a year-old post on Bendis' Tumblr finally makes sense.
The Tumblr post was a variant cover for "New Avengers" #1 by David Finch, which included the artist's depiction of Iron Man, Spider-Man, Wolverine, Captain America, Spider-Woman, Luke Cage and -- a character that never actually showed up in "New Avengers." However, Bendis clearly had plans for the unused design, accompanying the image with a quick comment: "Whatever happened to this guy? Marvel NOW! now?"
Although the mysterious character's identity has yet to be revealed, he showed up in this week's "Uncanny X-Men" #11 as the force behind a new breed of mutant-hunting robot. It's unknown what Bendis' original plans for the character were (many assumed it to be an alternate design for Ronin, and his placement with the Avengers suggest he was intended to be a hero at some point), it's clear that he's had an idea to reintegrate the design into his "Uncanny X-Men" run well before the series' start. Take a look at Finch's "New Avengers" #1 variant alongside the final page of "Uncanny X-Men" #11 below.