I did write up stats for the resulting being, because I was bored.
Size and Type: The entity maintains the incorporeal subtype. It’s size is the largest size of the composite mind lords.
Armor Class: The entity gains a deflection bonus to Armor Class equal to its Charisma modifier (if positive).
Speed: The entity has a 10 foot fly speed (perfect maneuverability) and a 10 foot land speed.
Abilities: It is considered to have the highest value of each of its composite mind lord’s ability scores.
Special Qualities: The entity has all the special qualities of the composing mind lords base creatures, with the following additions/adjustments
Absorb Equipment (Su): The base creature gains the ability to absorb magical or psionic items that take up body slots into its obsidian orb as a standard action that provokes an attack or opportunity, gaining all of the abilities of the item as if the item were worn. This effect lasts until a new item is absorbed into the same slot, effectively destroying the previous item. The standard limits on types of items utilized simultaneously still apply. The entity can use multiple items in each body slot. Each additional component mind lord allows the entity to absorb an extra piece of equipment into a body slot. In effect, three mind lords could combine, and then absorb three magical suits or armor. Any armor the component mind lords have absorbed is considered to be worn by the entity in this manner, and goes back to them when the duration is complete. Any newly absorbed equipment is sent to a mind lord according to the entity’s choice at the end of the duration.
Enduring Focus (Su): The base creature’s life force is tied to three obsidian orbs (see below). As long as its orbs are intact, the base creature cannot be permanently killed; its component mind lords reform 1d4 days after its apparent death. These mind lords can recombine at a later time so long as there are at least two of them and they use the metaconert power again.
Telekinetic Force (Su): The base creature can use a telekinetic force effect as a standard action that does not provoke attacks of opportunity. The save DC is equal to 14 + the entity’s key ability modifier (either Int, Wis, or Cha) + 1 per constituent mind lord (a result of metaconcert traits below). The sum of the mind lords’ manifester levels is the manifester level of the effect.
Metaconcert Traits: +1 bonus per constituent mind lord to save DCs that apply when manifesting a power or using a psi-like ability, +1 bonus per constituent mind lord when the entity makes its own saving throws in response to powers or psi-like abilities. Entity’s HP equals the sum of the HP of the Mind Lords, as well as all class levels, power points, experience points, powers, feats, skill points, ect. It lives 1 min./level + 1 minute for every additional power point over the requisite 9 spent on the power before splitting into it’s composite parts. It does not, however, age, nor can it be artificially aged: in effect, it is treated as if it were immortal like it’s components. It has all the memories of it’s components.