Abyssal Void Magus

By hunting the abyssal slimes he could make the area he could easily gain experience for not only his level but also for his skills.

When he was tearing each slime apart he focused on hitting the cores, he also kept frenzy bombs falling upon the enemy so that both spells would be gaining experience.

During this process he tried to ignore the lingering thoughts about the Queen's offer, he did not like the idea of being some breeding stock for a devil.

With the significant level differences between himself and the slimes it almost felt like he was hunting in the dungeon again.

The slimes were effectively large targets for his own spell and level grind.

He eventually had to start looking for larger targets since these were giving him a lot of experience but not enough to level up quickly.