The Boss: Dun-Dun-Dun!

Summoner-type mages.

Summoning skills can either be innate upon awakening or acquired through runestones.

It's typical to summon magical beasts the user has killed.

In that respect, they resemble necromancers, acquiring and storing souls before giving them bodies.

In theory, there is no limit to the number of summoned entities.

But if their number exceeds a certain point, the beasts can slip out of control.

Also, summoning beasts appropriate to one's dungeon level requires an equivalent amount of mana.

For that reason, most people can summon no more than five beasts at once.

A-rank and S-rank summoners may command several dozen, but... the mana cost greatly reduces their combat ability.

Summoners who are 'viable for actual combat' are quite rare worldwide...