How does nothingness in my world 1.7. 10 improve the soul level?

Hunting: Some monsters need enough hunting level to damage them, and increase their skill and experience by killing specific monsters. Moth, headless hunter, flame walker, monk, bloodthirsty bomber, blood fog, bloodthirsty wanderer, skeleton, dark beast, Nightcrawler, dwarf demon-1 can attack, increasing 7~20 experience. Fish 9. Jumper-5 can be attacked. ...