Called it. RIP more clones.
The cover of Volume 3 shows the goddess, the combined hero, the protagonist Raizel and Mersha. By the positioning on the cover, the hero and the demon lord are placed on a similar level, understandably due to their coming fight, but interestingly, Raizel is juxtaposed with the goddess.
I mean, if this insinuates that he's already close to her level (or stronger) I'm not gonna be surprised since he IS OP anyway...