The northern Spell Caster world had always been the most stable and peaceful place in the entire Spell Caster world. When the southern Spell Caster world was at war with Ozmu, many Spell Casters had entered the northern Spell Caster world, making the already powerful northern Spell Caster world even more powerful.
Furthermore, although Ozmu had finally won and occupied the southern Spell Caster world, some powerful Great Wizards from the Three Major Spell Caster organizations of the southern Spell Caster world had also entered the northern Spell Caster world in succession, and relied on help from the Seven Major Spell Caster organizations.
Therefore, when the southern Spell Caster world was in chaos, the northern Spell Caster world took the opportunity to expand its power. However, they now faintly regretted cooperating with Ozmu back then.