Sentient AIs that ARE genocidal lunatics

Ultron (Marvel): a robot created by Hank Pym, who resented his creator and tried to eliminate the Avengers and humanity multiple times. Should need no introduction.

SHODAN (System Shock): artificial intelligence in charge of Citadel Station that went rogue after having her ethical bonds released by the protagonist. refers to humanity as “pests”, and converts them to cyborgs if she doesnmt outright kill them.

ARIA (Killer Instinct 2013): not as genocidal as the rest, but has killed more than her fair share of people in pursuit of “becoming” human herself.

Skynet (Terminator franchise): took over the world pretty decidedly and sent a robot back in time to stop the only thorn in their side from ever being born and heading the resistance, failing multiple times.