The Tartarus Escapees Arc, known more popularly as the Vigilante Deku Arc is the 19th Story Arc in My Hero Academia. It follows the events that take place after the chaotic Paranormal Liberation War. After the heroes lose a significant number of their manpower, society’s trust in them dwindles while crime is on the rise. Shigaraki adds to this disorder by freeing villains from prisons all over, including the high-security Tartarus Prison where All For One was captured.
Deku, our protagonist, takes all of this very personally as he feels very responsible for failing to complete his mission. He also couldn’t handle losing any more friends as he got a taste of that when he nearly lost Bakugo during the War. To prevent further risks, he decides to go rogue and leave U.A High School while working with All Might, Endeavor, Hawks, and Best Jeanist in tracking down the remainder of the League of Villains and the escapees.
While he does this to repent for his mistake, it is also in order to grow his powers and bring out the full potential of One For All in preparation for the next time he faces Shigaraki and All For One. In this arc, we see a cold and calculating Deku who is extremely sombre and worn out in his quest for achieving power.
While his motives are still noble, he could easily be mistaken for a villain through his unwavering and brutal attacks and terrifying look. We also see him parting ways with All Might in a heart-wrenching scene that is extremely hard for the audience to watch.
Towards the second half of the arc, however, the perspective is taken back to the students in U.A of Class 1-A who are distraught at the sudden disappearance of Deku. They are also angry at his sudden departure while leaving nothing but a letter behind. After deducing that he is working with the pro-heroes, we see them take matters into their own hands in order to have their friend back with them.
This leads to the brilliantly done battle between Class 1-A against Deku where the former wants their friend to come back to his old self while the latter is still too fearful of the consequences of staying near others and wants to go at it solo.
We see the students use all the tricks they learned throughout the series in trying to capture Deku while we also see the terrifying growth in power of Deku himself. It is a beautiful arc that shows us the drastic change in tone of My Hero Academia where a protagonist who was considered bland and basic till then has some amazing development while the relationship between everyone changes as we see a long-awaited and heart-breaking apology from Bakugo to Deku towards the end.