So, the Piraka were great. They were the first wave of villain canister sets to have personality, and the lore benefited greatly from it. I feel that Piraka would be a great way to pay homage to the original series, but not as skakdi, so a few tweaks are in order.
“Welcome to to the Piraka Rehabilitation Center! Recieve much needed repairs and reprogramming, to help keep you running at top notch!” PRC is actually an asylum. This was made for the broken/insane matoran to be sent as a sort of Karzahni in the way G1 used it. The broken matoran were fixed, but the insane ones would be kept for rehabilitation. There were seven, however, that had been driven to such madness that any and all attempts for rehabilitation were futile, and often ended in the doctor needing treatment himself. These seven are as follows.
Hakann: A Mangaian known for his violent tendencies. While not stupid, he was not the brightest light in Mangaia. He enjoys having power, but above all, loves heat in a way that is obsessive even for Mangaians… Imprisoned for proclaiming himself as Tahu, and injuring several matoran who disagreed.
Vezok: A Nahoan who has descended to animalistic intelligence as a result of Vezon’s experiments. Imprisoned for inability to function in ordinary society and for attacking several matoran on his “first” trip outside.
Vezon: An Ihuan who was known for HER dangerous experiments with matoran efficiency. Known to put her results before her guinea pigs, several matoran have met their untimely ends at her hand. Remained undiscovered until Vezok’s incident. Imprisoned for her work and her death toll.
Avak: A Motaran weapons dealer. Dealt with shifty matoran and even rumored to be involved with the Brotherhood of Makuta. Not much is known about him, and he seems to hold silent for now. Imprisoned for a random attack, some suggest he was possessed, but he hasn’t been the same since.
Zaktan (changed): A Kanaean zoologist who specializes with bugs. Stung by an insect that made her delirious. She seems far more aware, but also off her rocker. Imprisoned for attempting to summon Makuta.
Thok: An Ihuan who practices dark magic, specifically illusions. He enjoys planning, and is kept under maximum security due to his powers and intellect. Imprisoned after another Ihuan discovered his practices.
Reidak: A Tironan whose perspective constantly shifts from the past, present and future. A result of Vezon’s experiments. Reidak was driven mad by his newfound powers. Imprisoned for bashing his head through a wall in a futile attempt to lose his powers, and injuring the matoran who attempted to restrain him.
This is just background information for the piraka, and doesn’t actually need to be used.
Story: The Rahkshi recieve a quest from Makuta, and are told the Piraka will help them on their quest. The Rahkshi break them out, and the piraka act as minions and scientists, and in the case of Reidak, an Oracle. When they join in servitude, spikes grow from their shoulders. These spikes are symbols of their new strength and power given to them from Makuta, but also a symbol of their enslavement.
Appearance: Since the piraka are matoran, albeit insane, they share many similarities. The main differences are the harnesses, which are printed on their torsos, and their spikes, which are a new element, or a reuse of the nexo knights Element used on some of the monsters.
The heads are modified too, their eyes are all disoriented, and their mouths are broken, giving them the impression of teeth. Their bodies are also dented and scratched in numerous places, as a result of them not caring about upkeep.
Here are some concepts, I am not an artist, but I think this gets the idea across.
If there are any questions, or if this contradicts something recognized as canon, please let me know!