Using Spheres of Power (SoP), what would the spell point cost be of a command undead greater ghost strike? Would it be 2 points, 1 for command undead and 1 for greater ghost strike? Would it be 1+ each undead you attempt to command within the cone effect?
As a standard action, you may make a ghost strike, summoning negative energy and throwing it at a target within Medium range as a ranged touch attack. A ghost strike is considered a negative energy death effect, and as such has no effect on undead, constructs, elementals, and other creatures immune to such things (although some talents provide exceptions). Ghost strike effects do not stack with themselves.
Some Death talents are designated (ghost strike), which provide you with additional types of ghost strikes.
Greater Ghost Strike
When making a ghost strike, you may spend an additional spell point to form your ghost strike into a Close-range cone, allowing you to make an attack roll against every target within this area.
Command Undead (ghost strike)
You may spend a spell point to make a ghost strike that grants you a measure of control over an undead creature (Will negates). For 1 minute per caster level, an unintelligent undead creature falls under your control or an intelligent undead become friendly toward you....