If you're looking for manga similar to Nanbaka 2nd Season, you might like these titles.
It took 430 years for the light of a star’s supernova to reach Earth - and when it arrived, the sky lit up for twelve days and people began to change, gaining powerful superpowers that terrified the populace. Over a decade later, these individuals are rounded up against their wills and shipped to a secretive island known as “Area D”, where they’ll begin a new life with the other “Altered”. Jin and Satoru are two such Altered who find themselves aboard a ship bound for Area D, where a survival of the fittest awaits them.
A blind boy, Shinobu, lives a peaceful life with the support of his kind teacher and girlfriend, Mikoto, training daily to learn the ancient martial art of self-defense known as “Mibuchi Toshujutsu”. Until one day, when all is stolen from him by a strange visitor who appears at the dojo. This man, defeating both Shinobu and his teacher, steals away Mikoto with him. Three years pass— In order to take back his girlfriend, Shinobu climbs up from the depths of despair, and finds himself at a remote island prison where only the most abominable kind of criminals are housed. There begins a battle royal, a free-for-all fight to the death with the villainous men within!!
On an island in the ocean, prisoners are sent to mine a mysterious and dangerous ore. One day, a soldier named Credo is sent to the island as a guard...
In a response to rising crime rates and public demand for stronger legislation, Japan has constructed an experimental site to "recycle" death row inmates... Death matches between murderers! With direct orders from the top, newly transferred Rei Minagawa is brought in to watch over Risa Suou, a fashionable murderer who only goes after criminals! Can a straight-laced cop and a moral murderer make it to the top?!
Nergal has been accused and convicted of heinous crimes involving magic. As punishment, he was sealed and sent away to prison to await death for forty days. The truth is though, he really is innocent! And, even though the guard Sunny befriended him...the boy's a total ditz! How will Nergal survive? At this rate, death may be more appealing than dealing with Sunny and the other prisoners and guards...
A secret island where only the most vicious criminals are sent to... the rules of society don't apply to Prison Island!
In a fictional world that believes in reincarnation of the soul. If someone accomplished great things in their previous life, the society expects that person to also be very successful in their current life. On the other hand, if one commits a great sin and is punished with a large prison sentence that far exceeds the life expectancy of that individual, he is forced to continue serving that sentence in his next life. This is a story of Haro Ahinsa and his reincarnations, that have been sentenced to 339 years of penal servitude for the his sin.