Mordeela

Mordeela was the home planet of the Kotturuh. It contained a gateway to another realm, from which the Kotturuh drew the energies they used to impose lifespans on other species. According to one tale, the name was from an old tongue and meant "judgement".

The planet was shielded by a barrier which kept it one picosecond ahead of the rest of the universe, with one weak point to allow Kotturuh ships access. (PROSE: The Knight, The Fool and The Dead)

History
A meteor believed to originate from Mordeela was discovered by scientists from Eloii. Crystals from it were used by Professor Hana Fallomax and her father to create the first prototype lifeshroud.

After discovering her immunity to their touch during their judgement of Destran, the Kotturuh took Estinee back to Mordeela as a prisoner. There she observed numerous dignitaries from across the universe coming to meet the Kotturuh in the hopes of bargaining with them to avoid judgement. She was eventually rescued by Professor Fallomax, who was mining crystals from Mordeela for her lifeshrouds. They caught Estinee again, but Fallomax rescued her from Mordeela a second time.

The Kotturuh recaptured Estinee on Andalia and were pursued to Mordeela by the Tenth Doctor and Brian. Arriving in underground tunnels, the pair encountered the revenants, individual members of each species forced to recite the date the Kotturuh had or would judge their species that were kept on Mordeela. They witnessed Fallomax rescue Estinee a third time and returned to the TARDIS. There, the Kotturuh confronted the Doctor and assigned him a date of his own, furious at his meddling.

The Doctor later ordered the Victis Fleet, equipped with lifeshrouds with a limited timespan of effectiveness, to go to Mordeela whilst he finalised his reverse engineering of the Kotturuh's power. After sentencing them to a lifespan of just fifteen minutes, the Doctor joined his fleet as they arrived in orbit. They watched Kotturuh ships fleeing beneath the barriers, which the Doctor assumed was because they wrongly thought it might shield them from his judgement. The Doctor decided to use crystals from Mordeela to reflect the Kotturuh's energies back at them, sealing off the gateway at the planet. Before he could launch this device however, his fleet was confronted by the arrival of a Dalek saucer, led by the Eighth Doctor, and a coffin ship, commanded by the Ninth Doctor. The two Doctors attempted to talk down their tenth incarnation, but he refused and ordered his fleet to fire, determined that Mordeela was going down with the Kotturuh. (PROSE: The Knight, The Fool and The Dead) During the ensuing Battle of Mordeela, the Tenth Doctor's fleet destroyed the planet. Despite his fleet being entirely destroyed or forced to flee, except his own ship, the Tenth Doctor was able to use the ruins of Mordeela to seal the gateway before escaping. (PROSE: All Flesh is Grass)

A crystal from Mordeela was one of the exhibits at the Verbier Museum of the Impossible. (PROSE: Canaries) The Dalek Prime Strategist also used the remaining Kotturuh crystals to provide himself with enough power to perform an emergency temporal shift out of the Time Vortex. (PROSE: Exit Strategy)

Behind the scenes
Mordeela appears as a card in the NFT trading card video game Doctor Who: Worlds Apart.