I was referring to the twice critical, the one that only multiplies the user's strength, the one they thought was Issei's but then they found out it was the Boost gear.
What do you think of the idea that the girls vote to give him some of Spiderman's powers or a sacred gear twice critical from dxd? I don't think they are such broken skills.
Good story, I hope you don't abandon it and you can add an auxiliary chapter with the names and images of the girls from the future harem of the MC, an image of the appearance of the MC?