Chamber, formerly Decibel of New Warriors volume 4, makes brief appearances in X-Men Legacy #264 and 265. These are his first appearances since his powers were re-set at the end of the Age of X mini-event. I’ve placed these issues in Limbo Part 4 Phase Six.
In the first issue, he appears on 2 pages, where we find he has become an instructor at the recently established Jean Grey School of Higher Learning on the site of the former Xavier Institute in Westchester County, New York. He’s teaching a class on coping with physical changes, presumably to help students whose mutations have manifested in altered appearances. His class is interrupted by Weapon Omega, who is immediately ejected from the building by Chamber.
In the next issue, Chamber appears in 1 panel among a series of mutants trying to help Weapon Omega, Mimic and Rogue eliminate the imminent explosions building with them due to the unique way Weapon Omega’s mutant energy absorption powers mixed with Mimic’s mimicry abilities. Chamber appears again at the end of the issue in a group shot of instructors and teachers outside the school.