Mission to Ralltiir
As a test of the training he had just finished, Darth Maul, a Sith Lord, was dispatched by his Master, Darth Sidious, whose training he had just completed, on a mission to Ralltiir. The purpose of this mission was the complete elimination of the leadership of the Black Sun criminal organization.
The battle
Maul engaged and defeated a large force of elite Black Sun soldiers on Ralltiir. Following this victory, he encountered and easily overcame the Vigos' bodyguards. He then systematically murdered every single Vigo present. Having destroyed the majority of the Black Sun criminal syndicate's forces, Darth Maul set his sights on completing his objective by killing Alexi Garyn, their leader.
Mighella, a Nightsister serving as Garyn's personal bodyguard, attempted to defend her master as the last line of defense. She confronted the pursuing Sith deep within Garyn's fortress on Ralltiir. The two powerful wielders of the dark side then clashed. Mighella wielded her darksword, while Darth Maul used his signature double-bladed lightsaber. After withstanding numerous strikes from the Sith Lord's weapon, Mighella's darksword shattered. She then unleashed a torrent of Force lightning upon him. However, Maul proved resistant to the Nightsister's attack and proceeded to slice her in half with his lightsaber, ending both the duel and her life.
Following this, he eliminated Alexi Garyn, but not before Garyn managed to inflict a chest wound upon him.
Aftermath
Oolth, Alexi's retainer, was the sole survivor of Maul's massacre. He attempted to inform the Jedi High Council on Coruscant about Maul's attack. Sadly, he was killed by hawk-bats before he could achieve his goal.