Mustafar
The planet of Mustafar was shrouded in legend. A once dark planet that had begun to heal, thick ash lay at the feet of the Ironwood Trees that surrounded the location of Vader's Caster. Darth Asminys stood for a moment at the periphery of the castle, staring up at the ruin of the building within which one of Emryc's gods had made his dwelling. Ancient history now. The man, or machine as some legends told, was dead and gone. But the darkness here remained.
Asminys continued his approach to the castle ruin, each step leaving footprints in the ash. Tugging on a chain that attached to a shackled and collared padawan, Asminys continued to walk the Jedi to his death. He supposed the Jedi learner knew that he was going to die, somewhere deep in what was left of his broken mind. Asminys had already taken some time to work over the padawan, extract what little secrets he may have known before deciding upon this fate for him after the strike on Ajan Kloss.
The lightsaber of the Grandmaster, Oota Boan, rode Asminys' hip, opposite to the one he carried since the days of the Cadre. The two lightsabers were a sharp contrast to one another, the black hilted and Sith rune carved blade of his own looked ill suited to be worn with the brown leather and clean light durasteel of the Grandmasters. Within the force the two were diametrically opposed, dark and light clashing on his hip as he walked, the light of the grandmaster's saber weighing heavily on his hip, insubordinate. Defiant.
As he walked into the shadow of the castle ruin, Asminys stopped. His red-gold eyes flicked to the shadows, where robed figures shuffled. They bristled with murderous intent.
Snap-hiss
The red blade of his lightsaber ignited from his fist as he swept the blade up, blocking a blaster bolt from the shadows. Sweeping his blade twice as more bolts came, he sent them flying back at their senders, striking them to the ground. He continued walking, tugging the chained padawan and pulling his grip tighter. These cultists would not stand in his way, nor would he allow them to harm his sacrifice.
A pair of robed cultists charged him with vibroblades while another retrieved one of the fallen blasters. Parry, strike and a cultist lay dead. The cultist retrieved the blaster and fired at him. Sweeping his blade from the dead cultist, Asminys' saber caught the incoming red bolt to send it into the other swordsman's leg. Batting the wounded man's blade aside, Asminys dispatched him with a swift thrust before tearing the blade out through the cultists chest to catch the last blaster bolt.
The last cultist dropped as the blaster exploded in his hand, crying in agony as the weapon exploded from the returned bolt. Continuing to walk at the same pace, Asminys buried his saber in the man's chest as he walked. Stretching his senses outwards, Asminys was satisfied to no longer feel the presence of life within the castle grounds besides the whimpering padawan that he dragged behind him. The only thing he could sense was the padawan's fear. The padawan's fear...
And Darkness.
Down below the castle.
Searching the castle, he found the stairwell and followed it down. Deep down under the ground where the heat of the world still burned. Where the darkness still dwelled. The descent seemed to stretch on, until finally he emerged into a large chamber. The lava had cooled long ago, leaving only obsidian rivers to ring the chamber, but the walls were still etched with runes of the Sith. Runes of power.
A broken henge ringed the altar at the center of the chamber, also carved with runes of the Sith. This place was a place of power. A place of Darkness. It had been used before and likely would be used again. The Darkside was strong here.
Asminys dragged the padawan before the altar, savoring the fear that radiated off the young man. It was the fear of impending death, and the padawan knew that his usefulness to the Sith Lord had come to an end. Taking the chain lead of the Jedi, Asminys flung it over one of the stones of the henge, letting it nestle into a crack in the rock before walking around and pulling it taught on the other side. Hanging the Jedi from his wrists, he secured the chain with a spike to the floor and observed his handiwork.
The Jedi hung in front of the circular stone altar, his toes barely touching the ground. Silent tears dropped from the Jedi's hanging head as he silently tried to come to terms with the imminent end. Asminys gave him no such time to contemplate.
Snap-hiss.
Asminys ignited the blue of the Grandmaster's blade. The hilt weighed heavily in his hand. Its movement was sluggish as he brought the tip of it to the Jedi's knee, and it seemed to resist him as he pushed it in to the scent of burnt flesh and bone. Repeating the process to the Jedi's other knee and his elbows, Asminys was satisfied as the Jedi cried out in pain with each burn. Satisfied that the Jedi's last moments would be spent in agony as he dangled there by burnt joints.
Deactivating the blade he turned and placed it on the altar. Walking around it, he took position opposite of the Jedi, his red-gold eyes meeting the Jedi's with a cruel glint of malice as the jedi shuddered, every movement wracking his body with pain. Asminys smiled. Oota Boan's saber sat on the altar in between the two of them, and Asminys turned his focus to it as he closed his eyes. Reaching his hands out towards the blade, he drew upon his hatred, dredging up the deepest pain and agony in his heart as the lightsaber began to come apart, floating into the air as its pieces began to shift and open, letting the pure blue kyber reveal itself to shine in the darkness.
Asminys would bleed the kyber black.
@Mr. Teatime