Your comedy is weak, at least make a post worth reading.
Between some of Nihilanth’s actual dialogue and later confirmation by Laidlaw, it has been revealed that indeed, Nihilanth had once been a slave to the Combine. Which makes sense given the surgical enhancements (biotechnology) that are apparent on Nihilanth are characteristic of the type of surgeries we have seen the Combine perform on humans (see similarity between Nihilanth and Stalkers).
It’s also pretty safe to assume that Nihilanth’s prime use for the Combine is for portal technology, given how Nihilanth can manipulate forces to transport armies and even parts of an envirnoment to another dimension.
The Combine and Nihilanth have not been explicitly connected through any in-game dialogue.