Kont_Archimedes
Hollow is a creature with the potential to have endless spiritual energies. Although the Bleach World limits the strength of Hollows to vasto lorde level, but if his system could allow him to access other worlds power systems like Esper, the mc might still have a chance to break this limit. Imagine if the mc was able to acquire or replicate all of Tatsumaki's powers and abilities (from One Punch Man). Also, don't forget that Mob Psycho 100 also has spirits in its Universe. Their is also the Yokai of Nurarihyon no Mago. They are somewhat similar to Hollow. Imagine the mc becoming half Yokai.