Upgrade Starts with Skeleton

What should I do if I am reborn as a little skeleton? No way! Add some more! As a skeleton, only the brain is left. It should be easy to use the brain, right? As a skeleton, it's normal to summon skeletons, right? As a skeleton, it's not surprising that he knows hundreds of millions of points of light magic, right? As a skeleton, it makes sense that he has hundreds of millions of human fighting spirit and martial arts skills, right?