Battle of Dathomir

"The time has come at last to take revenge on Asajj Ventress and the witch, Mother Talzin. I have learned Ventress has returned to Dathomir. Go there and wipe the witches out. All of them."

- Count Dooku ordering Grievous to Dathomir The Batte of Dathomir was a battle that occured in 20 BBY during the final stages of the Clone Wars. It was instigated by Count Dooku who, upon learning of the treachary of the Nightsisters clan, had ordered General Grievous and a large force of the Separatist Droid Army to Dathomir to kill Ventress and exterminate the entire clan as punishment for their actions against Dooku.

Background
During the Clone Wars, Asajj Ventress was a member of the Dark Acolytes and served as a commander for the Separatist Droid Army of the Confederacy of Independent Systems. She was a Dark Jedi Assassin and the apprentice of the Confederate Head of State Count Dooku but in 21 BBY, she was deserted and abandoned by Dooku by orders of his master, Darth Sidious, and she was supposedly killed onboard a Providence-Class Carrier/Destroyer during the Battle over Sullest.

She survived however and eventually returned back to her home planet of Dathomir and re-joined the Nightsisters, a dark order of female witches who specialize in magic, so she can get revenge on Dooku for his betrayal. After failing to assassinate him, she eventually got the aid of the clan mother Talzin who sent the Nightbrother tribal leader Savage Opress to become an apprentice of Dooku, only to betray him and Ventress later on. Dooku eventually found out about the plot and ordered General Grievous, the Supreme Commander of thr Droid Armies and a rival of Ventress, to go to Dathomir and kill Ventress along with the entire clan.

Droid Bombings
Upon recieving his orders, Grievous had gotten onboard a Providence Destroyer cruiser and commanded a fleet of four Munificent-Class Star Frigates, two Recusant-Class Light Destroyers, and a pair of Separatist Supply Ships and went into hyperspace into the Outer Rim territory. Upon exiting from hyperspace, Grievous had ordered an advanced squadron of Vulture Droid Starfighters and Hyena-Class Bombers to fly down to the surface of the planet and force the Nightsisters out from their fortress on the planet. The fortress would then be bombed by the droid bombers and the Nightsisters took cover as the Separatist forces began landing on the surface and sent out their troops.

Battle of Dathomir
The droid bombers continued their attack on the Nightsisters fortress after turning around for another run. Separatist landing crafts had arrived and began deploying B1 Battle Droids and Armoured Assault Tanks while Multi-Troop Transports had deployed B2 Super Battle Droids and all of them converged for the march towards the Nightsisters fortress to besiege it while it was still under fire from the Separatist bombers. One the supports eventually fell and the Nightsister, Karis, was hit by it. Ventress levitated the debris off of her and picked her up. Karis then said how she needed to defend the Nightsisters before dying shortly afterwards.

Ventress then activated her lightsabers and commanded the Nightsisters to battle against the droid army of the Separatists. During the ensuing battle, Ventress had quickly realized that the Nightsisters were outnumbered and were going to need reinforcements. Mother Talzin then went back to the fortress and found Old Daka where she asked for her to resurrect deceased Nightsisters and assemble the army of the undead. Daka resurrected them, and the Nightsisters had gotten the reinforcements they needed. Soon afterwards, the fighting had intensified especially on the eastern front, as the Nightsisters desperately tried to hold the line and save themselves from the vast droid forces.

Duel on Dathomir
With the undead backing up the Nightsisters, Ventress had new-found resolve and marched straight towards the Separatist landing site where Grievous was stationed at. There, Grievous exited his landing craft and faced Ventress and her army. The two then made a deal that if Ventress won a duel with Grievous, then the droid army would withdraw from Dathomir and if Grievous won, the Nightsisters would surrender. Grievous accepted the deal and fought in a lightsaber duel with Ventress. During the ensuing fight, Grievous was knocked down and ordered the droid forces stationed nearby to open fire on Ventress wounding her and killing many of the Nightsister soldiers in front of them.

During the fight, a wounded Ventress was being carried away by Luce but she was shot by a nearby B1 Battle Droid. Ventress held her in her arms and let go after with her dying breath, Luce warned that doom was upon the Nightsisters and told Ventress to go and save herself. Demoralized and horrified at the loss of so many of her sisters, Ventress withdrew from the battlefield and fled to the Nightsisters fortress instead.

The Massacre
Throughout the entire battle, Talzin had used her magic to torture Dooku from afar even while he was off-world. Using her sorcery, she demanded thath Dooku order the Separatist forces to retreat but he denied that demand. Dooku then limped over to the hologram table and told Grievous to kill Talzin instead and he followed through with it and Grievous marched towards the Nightsisters' fortress with the droid army. After wipping out what little resistance that was present, Grievous and the droids marched into the fortress and followed a trail of green mist to the location of Talzin.

Upon discovering the location, a battle droid blew a hole in the wall with a rocket launcher and Grievous marched in and killed both a nearby Nightsister guard and Daka much to the horror of Talzin. After Daka's death, the mist disintegrated and all of the undead warriors had fallen to the ground and died once more. Without their support, the remaining Nightsisters were all gunned down and slaughtered by the droid army and the entire clan was effectively destroyed.