VIOS

VIOS (Virtual Icon Of Sin), is an AI of demonic origins and the main antagonist of Doom II RPG.

Tactical Analysis
VIOS is, as the name implies, a virtual Icon of Sin. He interacts with Doomguy through corrupted monitors. When accessing these monitors, the player can either allow VIOS to corrupt the monitor's data, or delete it. If the player chooses to delete it, VIOS fights the player. If the player wins the fight, the data is deleted. The fights get harder the further into the game you go, and deleting the data weakens VIOS for the final fight.