Spear and Fang from the Adult Swim show Primal find themselves in the world of My Hero Academia.
It starts when Spear and Fang get frozen and are discovered by the League of Villains along with other creatures like the mammoths, bats, the giant spider, and the apes. During the USJ attack, Spear and Fang just awakened are freaked out at where they are and escape, killing various villains in the process along with the Noumu. The USJ attack leads to the League trying to attack the sports festival with the apes from episode 5 which leads to the festival’s cancellation but not before many students fight off the apes getting the interest of many pro heroes and one of the apes running off and eventually stopping Stain from crippling Tensei before said ape was caught, and due to different circumstances, Ochako, Tenya, Shouto, and Izuku intern under Gran Torino. This leads to an encounter with Spear and Fang that leads to Stain attacking only for the Hero Killer being offed by Fang. The League of Villains still get new members as Izuku, Ochako, Tenya and Shouto grow closer after surviving the Hosu incident. Eventually Spear and Fang run off to live nearby the Training Camp and when the Training Camp attack happens, more villains are killed as the various species unfrozen like the mammoths and primitive men wandering off confused at their surroundings leading to the villains being unfocused and Spear and Fang being disturbed eventually leading to retaliation. Shigaraki and All for One decide that Spear and Fang are too much of a threat to be left around and go to kill the two. After a hard battle to the point that you’d think All for One could win. Spear and Fang eventually win in a brutal finisher as the two are tired out. Spear and Fang now leave with the threat of the unfrozen animals still around as many pro heroes wonder what the hell just happen. Also during Spear and Fang’s attack on a villain, they cause enough of a distraction for Eri to escape eventually finding herself at U.A. before collapsing and being taken in.
It’s an Isekai because it has the central idea of being sent to or awakening in an unfamiliar world. As Spear and Fang find themselves in a different world.
