User blog comment:The Milkman/No Love For Leviathan?/@comment-4947725-20120917050702/@comment-5521671-20120917222421

Yeah, without thralls there isn't much the leviathans can do. Their mind control ability is very dependent on the spheres.

They just got a giant ego with all that apex race talk, but without soldiers delivering their orbs behind enemy lines they can't attack reapers forces.