For the Original, see here.
The Sword of Plun-Darr is the dark weapon of Mumm-Ra. It is the counterpart to the Sword of Omens and designed to wield the War Stone. When not in combat, the sword is kept sheathed within the Gauntlet of Plun-Darr. The sword had once fallen into the hands of Ratilla, but has since returned to Mumm-Ra.
At the height of Mumm-Ra's reign, before Mumm-Ra’s planetary invasion to acquire the War Stone, Mumm-Ra sought guidance from the Ancient Spirits to aid him in his quest for ultimate power. Under their direction, he was told that he would need a blade to channel the War Stone’s power. To do that, he would need the “blood” of a star to create such a fantastic weapon: The destruction of the Plun-Darr Star System.
After successfully collapsing the star, the Plun-Darr System was vaporized and its remains was absorbed by a black hole formed by Plun-Darr’s initial destruction. However, the “blood” of Plun-Darr (ore remains of the system) was acquired in the process via space probe. Once aboard his ship, Mumm-Ra had the Ancient Spirits mystically empower the Blacksmith to craft the Sword & Gauntlet of Plun-Darr. Once completed, he used the three power stones he had and implanted them into the gauntlet to bolster his power.
Unknown to him, his senior commanders, Leo and Panthera (Ancient ThunderCats), planned a rebellion shortly after the destruction of the Plun-Darr System. Using the surviving fragmented ore from the forging, the duo recruited the same Blacksmith to help them secretly construct the Sword of Omens to have an equal edge against Mumm-Ra. After Captain Tygus successfully retrieved the War Stone, Leo confiscated the War Stone to complete the Sword of Omens, but left the Sword of Plun-Darr incomplete.
Once the rebellion had taken action, Leo fought against Mumm-Ra in a clash between brethren swords. Leo ultimately defeated Mumm-Ra and stripped the power out of the gauntlet by removing the stones. Mumm-Ra fled into his sarcophagus and Panthera trapped him inside without the sword nor gauntlet. The pyramid ship crash-landed onto Third Earth due to the damage caused by the previous battle, but nobody recovered the Sword of Plun-Darr. It was later revealed that both the Sword and Gauntlet of Plun-Darr somehow ended up at the bottom of a swamp for several generations until King Claudus' time.
Ratilla's War & Cursing Plun-Darr
During the ThunderCats' reign, Ratilla somehow recovered the Sword of Plun-Darr within a swamp. Using its destructive powers, Ratilla used Plun-Darr to become a despot and had his rats start a war against Thundera. Unwilling to allow such dark power to prevail, the King at the time loaned Jaga the Sword of Omens to stop Ratilla. In another clash between the swords, Jaga's magic trumped over Ratilla in combat. As the Sword of Plun-Darr is filled with dark energies and too dangerous to be wielded by anyone, Jaga cursed the sword. The earth swallowed the sword and formed Mount Plun-Darr; those who dare enter the mountain will meet their demise.
Ratar-O's Excavation & Return to Mumm-Ra
After Thundera had fallen, the Lizard Army enslaved and sold many cats to the rats. Ratar-O, descendant of Ratilla wants to revive the glory of the rats by retrieving the Sword of Plun-Darr at Mount Plun-Darr. Using the cats as his own poetic justice, he forced many cats to attempt to mine and liberate the Sword and Gauntlet of Plun-Darr, but all were killed in the attempt.
After the ThunderCats had learned of the horrible fate of their fellow cats, Lion-O staged a rescue mission to save his people. Lion-O, Panthro, and Pumyra were captured in the process, but not Cheetara and Tygra. The duo pretended to be slaves and braved through the perilous cave to find the weapon. Because Cheetara is a Cleric, she was able to lift the curse and free the weapon, causing the cave to crash and also destroyed Ratar-O's lair. After Lion-O defeated Ratar-O, Cheetara and Tygra handed the Sword of Plun-Darr to him, but before they could celebrate their victory, Mumm-Ra's army had arrived.
Sensing the Sword of Plun-Darr, Mumm-Ra dispatched the Lizard Army to retrieve his prized weapon. Lion-O and Pumyra entered the mountain in attempt to distract their attention while the refugee cats escape. Unfortunately, the weapon is tied to Mumm-Ra and he used his connection with the weapon to act as a homing beacon to corner Lion-O and Pumyra. Not long after Lion-O passed the Sword of Plun-Darr to Pumyra, she was discovered by Mumm-Ra, and he recovered his weapon and held her hostage. Both Lion-O and Mumm-Ra fought against each other with their respective swords, but Lion-O bested Mumm-Ra by disarming him. To cheat his way to victory, Mumm-Ra knew Lion-O couldn't let a fellow cat die and distracted him by dropping Pumyra into the cave. While Lion-O successfully rescued Pumyra, Mumm-Ra successfully retrieved the sword and escaped with it.
Hunt of The Sycorax
Mumm-ra later used the sword to resurrect an ancient creature, the Sycorax. In a magical ritual, he summoned the power of the Ancient Spirits to merge his body and the Sword of Plun-Darr into the newly resurrected Sycorax to destroy the ThunderCats. Mumm-ra thought victory was at his hands as the Sycorax was unstoppable until Lion-O temporarily disabled the Sykalak with Ponzi's Miracle Elixir. Afterwards, Mumm-ra regained movement and continued his hunt for the ThunderCats. The ThunderCats attempted to stall the Sycorax until they could procure more elixir to stop Mumm-ra, but the Sycorax was unexpectedly defeated by Ponzi's caterpillar, Lucy. The insect hyper metamorphosed into a giant butterfly and fought against Mumm-ra. In a homage to Godzilla Vs Mothra, Lucy had the ability to crystallize objects and destroyed the Sycorax with it, forcing Mumm-ra to retreat.
The Sword of Plun-Darr is a powerful weapon whose power rivals the Sword of Omens, though Mumm-Ra comments that the Sword of Omens is only a flawed copy of the Sword of Plun-Darr as it was designed to tap into the Power Stones' full power. Its abilities include the following:
- Like the Sword of Omens, the Sword of Plun-Darr is able to change its length according to its bearer's will.
- In Legacy, it was shown that Mumm-Ra could transform the sword into a double-bladed weapon while fighting Leo (Lion-O) who was using the Sword of Omens.
- It can harness purple-colored energy (in contrast to the Sword of Omens' red energy) to enhance its own attacks.
- The toys for both the Sword of Plun-Darr and the Gauntlet of Plun-Darr inacurately match Lion-O's Sword of Omens and Gauntlet's coloring instead of having their proper Black/Purple and Black/Red colors.
- In Legacy, After Leo released all the other animals, the Sword of Plun-Darr's blades transformed to a saw-like form, giving it more of a resemblance to its 80's counterpart. The exact reason for this is Unknown so far.