Demon Clans
When the three pillars of light became clear to Ryu, his eyes narrowed.
Much like every other branch of Necromancy, Summoning Necromancer's were separated out into numerous branches. As the most powerful of Necromancers, one could easily expect that even though these branches might not be as infinitely variant as the other two main branches, they each had an overwhelming power of their own.
However, unlike other branches, rather than being separated by the way their corpses were prepared and the corpses they chose, Summoning Necromancers were separated by the branch of Nether World creatures that they formed contracts with.
From Ryu's limited understanding, weaker Summoner Necromancers would form contracts with individual creatures. Though they would always be considered weaker than their other branch counterparts, it was widely accepted that it was far more difficult to build up your repertoire along this path.