Microsoft now owns Activision Blizzard. While it isn't there yet, there is high anticipation that the Black Ops series will eventually be added to the Game Pass library. Why It’s Still Popular

Most sites offering "Black Ops II for free" are not authorized by Activision. Downloading from these sources usually carries significant risks:

Even years after its release, Black Ops II is considered one of the best in the franchise because of its branching storyline, the introduction of the "Pick 10" system in multiplayer, and the iconic Origins and Mob of the Dead Zombie maps. Playing a legitimate version ensures you have access to the official servers and a community that is still active today.

Pirating copyrighted software is illegal and can lead to issues with your Internet Service Provider (ISP).