After the incident at the Sheol Gate, Ragna lets Noel Vermillion travel with him for a short time, though he tells her to leave afterwards, upsetting Noel who tells him that the next time they meet they will be enemies. He is shortly thereafter attacked by Carl Clover, managing to beat the boy though he is dealt a nasty blow from Nirvana. He then wakes up in the Kaka Clan village, having fallen in there and spends the next few days recovering and becoming friendly with the Kaka Clan, including Taokaka.
He leaves shortly thereafter and meets Platinum the Trinity before fighting Lambda-11 due to Kokonoe messing up the teleporting process. After fending her off, Ragna hears from Kokonoe not to fight Hazama as he can’t beat him. Hearing Noel’s name from Kokonoe prompts Ragna to find Rachel who tells him where to go, though reminding him that he mustn’t fight Hazama. He then runs into Jin at the Librarium branch, and he manages to beat Jin. There Jin also warns Ragna not to fight Terumi, saying Ragna cannot beat him.
Nonetheless, Ragna proceeds to fight Hazama, though his Grimoire is useless as Terumi, the original creator of the Azure Grimoire, locks Ragna’s. Ragna is forced to watch as Noel descends from the Cauldron as Mu-12. Just as he is about to be killed, Nu intervenes in Lambda’s body and gives Ragna Idea Engine, allowing him to bypass his Azure Grimoire’s restrictions and allow access to the true Azure and defeat Hazama. He runs to Rachel to free her from a binding spell and then fights Mu. Ragna manages to wake Noel’s mind by using the True Azure’s power to activate the Idea Engine though in the process his left arm is destroyed. After the fight, he, Jin and Noel see that Hazama and Relius Clover are working for Saya, which is a shock to them. After they leave from Kagutsuchi, he, Jin and Noel decide to leave the city and become stronger. Kokonoe gives Ragna a new mechicanal arm using Lambda’s parts.