RaedaX_1
honestly, I don't like the idea of him using anything from Shin's shop. it feels like accepting the collar on his neck if a weak Dante uses Shin items to become stronger directly, he'll be too embedded in Dante's foundation and you never know if Shin will be able to rip that power away from him. He should look for something like The Bloody Palace, a place where he can fight and slaughter without touching earth's human population.
I think it would be better to equip Dante with weapons from his other versions. In addition to allowing you to improve them with souls and themselves after reaching certain limits to spend them. You could also give it a transformation like in the games, giving it, in addition to the devil trigger, an angel trigger or a fusion of the two, I don't know. Avoid giving it too many power-ups, the story goes at a good pace, let the MC develop slowly and not as fast as other authors do in their stories, these are my thoughts and ideas, I hope they are taken into account and that they have been helpful.