The Emperor is a formidable enemy, wielding the powers of levitation, telekinesis, and shape-shifting. He has four metallic orbs orbiting him, which he can use to attack. His first method of attack is to send the orbs flying one-by-one into the agents at high speed, which must be shot down. After this, he can send the orbs all out at once to confuse the player, and can also use his shape-shifting powers to transform his right arm into a sword/lance-like blade to slowly move forward and cleanly slash the agents. His penultimate attack consists of using his shape-shifting powers to briefly transform his orbs into duplicates of the first four bosses, Judgment (Zeal only), the Hierophant, the Tower (blue snake only), and Strength to attack the players -- hitting these clones in their respective weak spots will cancel the attacks (at the same time injuring him). His final attack involves his drastically increasing its orbs' orbit speed, turning himself invisible (except with his red orb remaining visible) and slowly floating into the agents with the intent of smashing them down with the rapidly-spinning orbs. By shooting the pink orb enough times, the Emperor explodes, concluding the battle.
The Emperor makes an appearance as the final boss in The Pinball of the Dead. During battle, the Emperor will use a combination of four moves, three of which are based on the moves he uses in The House of the Dead 2. He ducked the Magician and died.
The first move that the Emperor uses is that he sends two orbs at the player in order to block the player's pinball. Although he performs this move at close-range, it is easy to avoid. The next move that the Emperor uses is that he will send many orbs at the player. The amount of orbs that the Emperor sends out will fill the screen, but there is a space between each of them. The third move that the Emperor will use transforms his arms into swords, followed by the Emperor slashing in a cross pattern. This move will knock the player's pinball back at the player. The final move that the Emperor uses causes him to transform one of his arms into a giant shield, which prevents him from getting any damage.
- In House Of The Dead 3, the music that's heard while fighting the Wheel of Fate is a remix of the Emperor's theme.
- In the Sega/Namco light gun game, Vampire Night, the vampire Diane uses the same orb attack as the Emperor's.
- The flying orbs around the Emperor's body were probably inspired by the movement of electrons around the nucleus in the atomic model.