Shadow Guardians is a 5th level spell from Races of Destiny, which creates a number of 4 HD mindless constructs that are A. Phantasms, so while they "exist", they are illusory (they are, implicitly, 50% real), and B. will follow one order for the entire hour/level duration, with an additional trigger causing them to attack. You create a number of these things equal to your level.
Now, I'm wondering what can be done to boost them; I'd kinda like a little something that brings them all up from "suck" levels, which, considering they are mindless constructs...