WARNING: The following contains spoilers up to My Hero Academia #294, by Kohei Horikoshi, Caleb Cook and John Hunt, available now in English from Viz Media.
My Hero Academia's League of Villains is a band of misfits and societal outcasts that – unlike most of the heroes – have all received backstories and individual character moments explaining why they are the villains they've become. With Tomura Shigaraki's dark childhood, Spinner's past of mutant Quirk discrimination in his village, Dabi's true identity as Toya Todoroki and Himiko Toga's inability to forcibly suppress her Quirk to fit in, every League member has more to their story than meets the eye.
Now, in My Hero Academia Chapter #294, Mr. Compress becomes the final member of the League to reveal his backstory... in what might very well be his final appearance.
Throughout the War Arc, momentum has seesawed between the heroes and villains. The villains seemed to be winning the day up until Best Jeanist leaped down from a plane to restrain Gigantomachia with steel cables and Mirio rushed in to provide assistance in a surprise comeback. This left the villains on the ropes with the finale fast approaching. Considering both Shigaraki and Gigantomachia are down for the count, it looked inevitable that not only would the heroes win the day yet again, but they'd even be able to arrest every prominent member of the League with the possible exception of Himiko Toga.
However, true to his magician persona, Mr. Compress pulls out a last-second trick in a bid to turn the tides yet again. By compressing himself in a move that entails ripping out his own body parts, Mr. Compress frees himself from Best Jeanist's steel cables. Thanks to this, he's able to aid his allies and give them one final shot at escape – but at the cost of what Mr. Compress believes will be his own survival.
It's during this sacrificial maneuver that Mr. Compress reflects on the story of his life and how he found a family in the League of Villains. He reveals that his grandfather was the infamous thief Oji Harima, a Robin Hood type figure who stole from the rich and gave to the poor. In the My Hero Academia world, Oji Harima stands among the ranks of legendary villains alongside the all-powerful All For One and the terrorist leader Destro.
Mr. Compress mentions how it's always been his ambition to live up to his grandfather's legacy, but that if he doesn't act here, he'd be sacrificing the dreams of all his friends in the League along with his own. It's a moment that humanizes him, especially since his true face is shown for the first time. In yet another surprise twist, the general fan consensus seems to be that he's more attractive than anyone expected – his proper mannerisms and ambiguous age led many to believe he was an elderly man.
With so much hanging in the balance, including Mr. Compress's ultimate fate, the next few chapters seem likely to finalize who survives this arc and who perishes on the battlefield. It'll be a huge loss for both fans and the League of Villains if Mr. Compress dies just as we're getting to know him.