X-Men Legacy #250
Though not billed on the cover as an Age of X aftermath issue, this Giant Size milestone issue of X-Men Legacy (wow – has it really been 20 years and 250 issues since a comic book sold 8.1 million* copies?) contains a ten page Age of X epilogue story about the mysterious Revenant character. Likely because it has the most unimaginative title a story could have, “Flashback” is only titled in the intro page, where readers are warned of the abrupt change in artist as Steve Kurth, Age of X artist, takes over midway in the book from Koi Pham. Northstar appears as a regular member of the X-Men in flashback, and there is a possible appearance of Box’s foot.
Right before Revenant’s ghosty naked form finally leaves, a recap of various Age of X events dizzyingly radiates in reverse order from top left to bottom right across a two page spread, with the very first panel showing an image of Northstar crouching down just after reality is returned to normal. This image is a faithful reproduction of the same scene Steve Kurth drew in New Mutants #24, the last numbered issue of the crossover.
In a jagged corner of one panel on the same two page spread, a foot which may belong to Box appears. Unfortunately not enough is shown for an exact confirmation but Box was present in the depicted scene, so it is possible.
* – in 1991, the first issue of this title, the adjectiveless X-Men #1 sold a very large number of issues. It’s generally agreed that it is at least a 7-figure number. Some place it as high as 8.1 million, but I hereby disavow any actual knowledge of what the actual number might be. Since 8.1 million is the highest number I found on the Internet, I’m using it to make my point and for the fun purpose of intentionally spreading unverifiable information, so please no flames. If you know the exact number, please leave a comment.