Just picked up this addition for spheres of might over on drivethru.
It's basically a Sphere version of the Leadership Feat. Only given it a quick look but it has some very neat things in it and various options around Conhorts and Followers.
The Leadership sphere is not about leading people into battle (that's the Warleader Sphere). Instead it's about recruiting allies and leading organizations.
Has some neat Archetypes too.
One in particular is a Wraith Archtype called - The Collective, allowing you to play a Hivemind. A Disembodied intelligence giding and manipulating your collection of Followers and Cohorts