Using D&D settings and generics for a fantasy manga is fine. But the blatant copying of 3.5ed stats and rules, while also lacking any reasonable explanations of how those apply, just annoys me. The worst bit so far is how they tried to incorporate daily spell limitations... Ffs that exists as a game balance thing so spellcasters arent too op compared to other classes, and the actual in-game reasoning revolves around the fact that you have to spend mana AND keep the extremely complicated verbal mumbojumbo and finger wiggling fresh in your memory (after youve spent the requisite effort to learn and comprehend those spells in the first place). Here, theres no explanation or reasoning given at all.
This has potential, but the worldbuilding is too reliant on the reader already having a comprehensive understanding of how D&D works. Flesh this stuff out more, at least explain the quirks that you put into the story. Or cut out the D&D rules info and just use the setting material. Frankly, that would make this a lot more immersive.