OK, I believe would be considered an update.
Don’t quote me on that, though.
Anyways, @Gilahu wrote a great backstory for these two, so, here it is:
Sachel was the chief librarian of the Brotherhood of Makuta. Originally he just kept all the Rahi creation recipes in order, but after the Brotherhood began having a military presence within the Matoran Universe and especially after Miserix assigned Makuta to the various regions, Sachel’s tasks expanded considerably, since Miserix wanted the library on Destral to include every bit of knowledge the Brotherhood gathered.
This also included the archival storage of important artifacts, which grew to be Sachel’s favorite sector. He would spend more and more time acquiring interesting and valuable artifacts or at least replicas of them to add to his collection.
The former Matoran Shamsel became his assistant after Mutran got weary of him and dumped Shamsel into some mutagenic substance before casting him out of his laboratory.
One day rumors of a mysterious mask reached Sachel, that was said to make its wearer immortal. Intrigued, he set off to find it, taking Shamsel with him.
And indeed the rumors proofed true. He found the mask hidden on some remote island, a thing that was all jagged edges and gleamed in a cold, cruel golden light.
Sachel sent Shamsel back to Destral with it, while he himself traveled on to Stelt, to collect some other valuables that had ended up in Jsasax’s hands, just to learn upon his return that his assistant had been attacked, robbed and killed before he reached the Brotherhood’s fortress.
The trail led Sachel to a Matoran village, protected by two Toa of which one had died recently. The remaining one, sick with grief over his fallen comrade, had set out on his own to find the fabulous “Mask of Immortality” and when discovering that the Makuta nearly had it safe inside their fortress, became desperate.
When Sachel arrived, he was just placing the jagged mask over his friends face.
Sachel walked towards the small hut where the fearful Matoran had told him he could find the Toa. He hated this kind of solving problems, but murder by a Toa on one of the Brotherhood’s servants couldn’t be tolerated – and besides, all those pumped up so called “warriors” of his fellow Makuta were more likely to raze the whole village to the ground, stepping on the mysterious mask in the process or damaging it otherwise. He snorted. At least one Toa shouldn’t proof any problem.
He opened what passed for a door on this ramshackle building by ripping it out with gravity and flinging it away, exposing the view on a Toa of Plasma, no, two Toa, the Plasma one was bent over one of Plantlife. Apparently a dead one since his heartlight didn’t flash. What immediately caught Sachel’s attention though, was that the Toa of Plasma was just placing the jagged mask he had stolen over the other Toa’s face.
“So here you are”, Sachel growled and stepped into the doorway. “Explain yourself, Toa, and maybe you’ll-”
The mental blast that suddenly blew through his mind was horrific. Sachel tumbled back a step, then fell down to his knees, as his legs gave way under him. His vision blurred and he was just dimly aware of the Toa of Plasma collapsing also, while the dead Toa slowly rose – not by lifting his arms and legs, more like he grotesque puppet of some user of telekinesis, arms and legs dangling while he floated half a bio above the ground. His eyes began to glow in a piercing cold blue.
Sachel’s head felt like it would split open any moment, but he mustered all the mental strength he had and turned it into a shield that deflected the attack enough, that he could think clearly again. Whatever just happened, there was no way a Toa of Plantlife could muster psionic powers strong enough to nearly knock out a Makuta with a single blast.
Slowly Sachel got up again, trying to scan his surroundings while keeping an eye on the floating form of the Toa. The Matoran who had followed him were all dead, as was the Toa of Plasma and the Rahi in the nearest pen. A mental blast strong enough to outright kill.
The dead Toa’s mouth opened and he began to speak in a voice that sounded like a Toa’s, but at the same time didn’t.
“At last I am free … but this body … is weak. No way to channel my power. You have withstood me, mortal. I sense your might.Yours will suit me better…”
“Who -What are you?” Thinking was difficult. Still the mental storm was battering at his defenses. And it originated from this thing. He had to stop it and get that mask.
“I am …?” For some reason the question seemed to startle the creature. “I am the immortal … Kivri. Kivri, … Toa of … Plantlife? No, that was before …”
Sachel never had bothered to study tactics or hone his fighting skills and reflexes, but he knew an opportunity when he saw one. He brought up his palm and blasted the thing in the hut with a bolt of Chain Lightning, then used Gravity to collapse the building on it.
Or at least he tried, but the building wouldn’t collapse. He focused more of his power on it, but all that showed were fissures, while the walls and the roof stayed in place. Then the whole thing suddenly blew outwards, stone shrapnel piercing his body and bouncing off his armor and mask.
While his Quick Healing ability set to work, the dust dispersed and he could again see his opponent, a black crater in the Toa’s chest marking the spot where he had hit it with his lightning bolt. He flung another one in the things direction, but this time it was stopped halfway there – simply caught in the air. The combined powers of half a dozen Toa of Psionics wouldn’t have been able to accomplish this. Still Sachel was ready for the riposte when it came, lowering his body’s density so that the reversed bolt of lightning passed right through him and struck another hut, setting it afire.
“You’re tough, eh? But let’s see how much it distracts you when your body is all over the place.”
Sachel reached for his magnetic powers, focused them on the limply floating form of the Toa and then pulled in opposite directions. Nothing stopped him this time, the Toa’s body was cleanly ripped apart. When he stopped everything just fell to the ground.
He allowed himself a smirk. Whatever Psionic abilities that thing possessed, let it try assembling itself the right way only by telekinesis. Sachel approached a few steps, then stopped. The eyes behind the mask still glowed and seemed to follow him.
Carefully he ripped the head loose from its half of the body, then pulled it to him with gravity. The power this dead Toa had used had to originate from the mask, but he wasn’t sure what role the body had played in it. The thing most definitely wasn’t entirely dead yet – even though it now was no more than a head with a mask. Perhaps all that “Mask of Immortality” stuff wasn’t entirely wrong.
When the head reached him, Sachel extended a hand to pull the mask loose from it, but the moment his fingers brushed the cold metal, he felt a presence blowing through his mental defenses like an avalanche, unstoppable and terrifying.
He tried pulling loose from the mask, but his body didn’t obey him anymore. His mind was in turmoil, something rooting through his memories, studying and then erasing everything. Sachel could do nothing but stand by and watch, while his very identity began to vanish, his knowledge seeping out of him, leaving nothing but emptiness. He tried to use any one of his powers to stop what was going on – no, he didn’t even know what was going on anymore, he just wanted it to stop, to leave him alone.
“What? What was this?”
He couldn’t even say if the voice was his or that of someone else, if it was just inside his head or outside, too. Nor could he make out what it was talking about. Who was he, anyway? Pain shot through the thing that was him, just for a short instant. Then the Makuta named Sachel was gone.
The Rahi looked down at the armored figure. It had no idea what had happened to this one, but it tasted bad. The Rahi spat out some fingers. Well, it didn’t matter if one tasted wrong, there were so many others to feed from. Surely some of them would be better tasting. If it remembered correctly, the little ones always had been particularly delicious.
It trudged away from the dead Makuta, sniffed at the remnants of Toa Kivri, then went over to the nearest Matoran, as it decided that there was too much armor there, too. A feast was served and it wouldn’t waste it.