Sheltem is a recurring villain from the Might and Magic series, acting as the main villain in all installments since the first title (Secret of the Inner Sanctum) up to the fifth title (Darkside of Xeen).
Sheltem is a Guardian, an android created by the Ancients, a technologically advanced race which existed since primordial times. As part of the Great Experiment, the Ancients have seeded the universe with flat, square-shaped worlds known as "Nacelles". To each Nacelle they would designate a Guardian, a sentient android with advanced magical powers and tasked with protecting his Nacelle, especially from the evil Kreegans. Sheltem was designated as the Guardian of Terra, the Nacelle from which the Ancients have originated, being programmed to both obey the Ancients orders and to protect Terra from any harm.
In order to better accomplish his job, Sheltem engages in experiments in self-sufficiency, which eventually draws the attention of the Ancients, who disconnect him from the Wire (a universe-wide network which both Ancients and Guardians used to communicate and draw power). Knowing the Ancients would send agents after him, Sheltem lowers his power emanations and enters in stasis to prevent them from discovering his plans. The Ancients, not willing to take chances, create another Guardian, Corak the Mysterious, and send him to capture Sheltem for repairs.
Corak arrests the asleep Sheltem and takes him to a off-world repair facility. Due to flaws on his programming, Sheltem interprets his capture as the Ancients interfering with his job as protector of Terra, thus making his two directives conflict with each other. As to not receive any orders, Sheltem temporarily disables his auditory sensors and confronts Corak and another agent, putting them in stasis, after which he uses the ship's computer to erase his first directive and reprogram himself to be able to feel emotions.
Might and Magic Book One: Secret of the Inner Sanctum
With the ship not having enough fuel to return to Terra, Sheltem is forced to land it on VARN-4 due to it being in close proximity. Once landing, however, he discovers there is no fuel on the planet for the ship, and it would take years for VARN-4 to reach Terra on it's own. Enraged, he connects to the Wire and drives another VARN into the sun, deciding to abuse his time on VARN-4 before he could drive it into the sun and return to Terra.
Sheltem imprisons the benevolent King Alamar and impersonates him, taking his place as king and starting a tyrannical rule by doubling the taxes on the citizens and releasing monsters into the land. A group of adventurers seeking the secrets of the Inner Sanctum confront King Alamar, blowing up Sheltem's disguise. To prevent a direct confrontation, Sheltem banishes the adventurers into a dungeon, but knowing that Corak was already after him he decides to escape, using a Gate to Another World to flee. The adventurers eventually find their way out of the dungeon and release the real King Alamar, using the Gate to Another World to pursue Sheltem.
Might and Magic II: Gates to Another World
Sheltem arrives on CRON, but since the planet's security system were alerted to his presence he decides to hide himself. He uses this opportunity to ambush Corak, separating his head from the body. When the adventurers arrive on CRON, Sheltem reconnects into the Wire and takes over the planet's security systems, placing a backup of his personality into the main computer to drive the planet off it's course, steering it towards the sun. While the heroes are busy trying to save the planet, Sheltem escapes again. However, the adventurers rebuild Corak and stop the planet.
Might and Magic III: Isles of Terra
Sheltem manages to arrive back at Terra, so he reconnects to the Wire and starts to implant the VARNs on Terra while driving the remaining CRONs into the sun. However, Corak was hot on his trail, having formed a new group of adventurers to stop him. They invade Sheltem's ship, forcing him to confront them. However, he is outnumbered and defeated, being forced to flee from Terra in a spacecraft. Corak gives pursuit in another spacecraft, while the adventurers follow them in a third spacecraft. The adventurers, however, are thrown off-course, never to be seen again. (Or so the narration claims; they would appear later in the seventh game.)
Might and Magic IV and V: World of Xeen
Sheltem safely arrives on XEEN, while Corak crash-lands on a volcano and gets trapped within his ship. XEEN was a world split in two levels: the Clouds, high above the sky, and the Darkside, on the ground level. In order to take over the planet, Sheltem creates a undead minion called Lord Xeen, whom he tasks with conquering the Clouds, while he himself conquers the Darkside. Once again taking the guise of Alamar, Sheltem begins his plans by either killing, imprisoning or capturing the servants of the Dragon Pharaoh, XEEN's Guardian, kidnapping Queen Kalindra and amassing a personal army to besiege the Dragon Pharaoh's pyramid. The Dragon Pharaoh muster his force to battle, but decides to order them to surrender while sealing himself inside the pyramid.
Lord Xeen succesfully takes over the Clouds and imprisons the prince Roland on a isolated tower. Roland sends a telepathic message asking for help, and eventually a group of adventurers who received the message in their dreams gather together to fight the lich. The new heroes defeat Lord Xeen and cause his castle to disintegrate, but soon after Sheltem appears on a visage and taunts the group. Prince Roland then leads the group into the Darkside, where they discover it has already been taken over by Sheltem.
Sensing the heroes presence, the Dragon Pharaoh attempts to contact them by sending a hatchling carrying a orb. Though Sheltem blasts the hatchling, the orb falls intact to the ground and is eventually picked by the heroes. Following the Dragon Pharaoh's instructions, the group contacts his remaining allies and eventually rescue Queen Kalindra, who takes them to the Dragon Pharaoh himself. He reveals that when Alamar arrived in a shooting star, another star felt on the volcano, so they go to investigate it only to find Corak still trapped on his ship. With the help of the Dragon Pharaoh, they obtain a Soul Box, with which they could carry Corak's essence inside Sheltem's castle without him noticing. The adventurers invade the castle and finally reach Sheltem, opening the box to release Corak. The two fight each other to a stalemate, so Corak, in a last desperate effort, grabs Sheltem and activates his self-destruct device, killing them both in the process.