If you are referring to the NRaas Hybrid mod, it is available from our site, not from ModTheSims.
http://nraas.wikispaces.com/Hybrid+Phase+Five
The Hybrid mod improves the playability of hybrids that are formed by other mods or an EA glitch by providing the full interface and range of commands and skills for each occult state that the hybrid might have. So, for example, a Genie/Witch/Faerie has both witch and faerie energy meters (one from the left side, one from the right) and can do anything that any of the three single occults can do.
But the mod does not, by itself, cause or allow the creation of hybrids. Under EA standard, one of the occult states always wins out. You would need additional mods or something else to allow their creation. Within the NRaas suite, that would be MasterController (player can add occult states to a specific sim on demand) or StoryProgression (allows for mixed occult parents to give birth to hybrids via a percent chance setting, as well as allowing inheritability to grandchildren if a generation gets skipped; also allows hybrids to form when new sims immigrate to your world).
And finally, of course, we inject fresh viruses into all of our mods daily just to annoy people. No, just kidding, downloads from our site are perfectly safe. :)