Is Mewtwo dead?
Since Mew has an immortal life force, Mewtwo did not die like the other clones, but grew wrathful that humans had made him to serve. So he escaped his tank and destroyed Dr. Fuji and everyone else in the lab.
Are there 2 Mewtwo’s?
There are at least two Mewtwo in the anime. First, we have the original Mewtwo, which we see in Mewtwo Strikes Back, Mewtwo Returns, and during the episodes of the anime where he is at Viridian’s gym. The second Mewtwo is in the Genesect and the Legend Awakened.