2) Guilty Spark’s Betrayal – Halo: Combat Evolved
With the Flood on Chief’s radar, the supersoldier makes it his mission to recover the Index, a key that will unlock Halo’s weapon and purge the threat once and for all. Aiding him is the egocentric Guilty Spark, a maniacal one-eyed robot who convinces Chief to take the steps necessary to securing the key.
Once successful, Guilty Spark transports them back to the Control Room where he urges Chief to take the next step and activate the ring. But Cortana intervenes, revealing that Spark is out for his own gain, and that the Index will not only demolish the Flood, but all life on the planet.
Betrayal complete, Chief averts disaster just in time, and the scene cements Guilty Spark as one of the series’ most memorable antagonists.