Many Mythic Paths in Mythic Paths of the Lost Spheres support multiclass characters but as of yet there aren’t many multi-path mechanics out there despite the Dual-Path feat. But the possibilities are endless for path interaction and one such option exists for a Scion-of-Sorcery that command the hordes of a Hivemaster:
For the Scion-of-High-Sorcery and Hivemaster mythic paths from Mythic Paths of the Lost Spheres:
Sanguine Slavery (Mythic)
Your magic causes the power of your servitors to come alive within your own blood.
Prerequisites: Dual-Path feat, Power of My Kin primacy and the What is Mine Hivemaster path ability.
Benefit: Servitor creatures can be considered blood-relations for the for all Hivemaster and Scion-of-High-Sorcery abilities. Additionally, spell-like abilities of these creatures are now considered spontaneous arcane spells known by them. For more information on Servitor creatures see page 14 of Mythic Paths of the Lost Spheres.