Quick and Dirty Lore:
Kirop is a Shadow Matoran. Once just a normal Matoran living in Karda Nui, Kirop was infected by Shadow Leeches and became an assistant to a Makuta named Chirox (8693) by clamping onto his back while in battle with the Toa and fellow Matoran who did the same.

Full lore's gonna be late tonight, I really need to eat

crazy that there were 12 more Bionicle sets that year than there were Star Wars!

During the creation of the Matoran Universe a power source was required to keep the machine running, and so Karda Nui was created. The Great Heart was a massive power plant that provided electricity to every corner of the MU, and its maintenance was entrusted to a special breed of workers. The Av-Matoran, the Villagers of Light!

The Av-Matoran were stationed in a complex network of tunnels and caverns that linked the roof of Karda Nui's dome to the floor of the Southern Continent's dome above. There they would monitor the powerplant's output and make sure power was being diverted correctly.

But the Av-Matoran had one slight problem. A Toa of Light had never been created, much less a Turaga of Light. Who was to lead the village? The Matoran Kirop stepped up to the task and became the "Turaga" of the Av-Matoran, keeping peace among his people and handing out tasks.

For eons the Av-Matoran lived undisturbed in their hidden chambers. That was until the Great Cataclysm! Thanks to Maktua meddling elsewhere a massive explosion took place in the heart of Karda Nui, punching a whole through the roof of it's dome and into the ocean above. Automatic pumps kept most of the water out of Karda Nui, but the plant as a whole shut down.

Water continued to flood and drain from the chamber. First it brought sand and sediment, creating a vast desert. Then came plants and algee, birthing a grand swamp. All the while sediment built on the ceiling creating gigantic stalactites. Eventually these stalactites became to heavy for Karda Nui's damaged roof, and the chamber caved in! The stalactites embedded themselves in the swamp bellow, dragging down the Av-Matoran chambers and villages built on top of them.

Under Kirop's guidance the Matoran of Light adjusted to their new home, spending the 1,000 years after the Great Cataclysm for Mata Nui to reawaken.

But as Terdiax's grand plan came to fortition, the Av-Matoran became subjects of a dark experiment. The mad scientist Mutran had just finished a devious new creation, the Shadow Leech. A vile slug, the Shadow Leech could drain the moral light of an induvial, leaving them a slave to the Maktua's dark whims, and would create a shadow barrier to keep light from returning to them. After small tests here and there around the MU the Makuta where ready for their final mission. 7 of their best generals would travel to Karda Nui and use the Shadow Leeches to enslave the entire Av-Matoran race, preventing the creation of any new Toa of Light and opening the potential for a Toa of Shadow.

Kirop was one of the first to fall, and with him gone the other's soon followed until only one small settlement was left.

But the Av-Matoran weren't without hope. When Matoro sacrificed himself to revive Mata Nui (long story) it created a bright blast of light inside of Karda Nui. This light blinded three of the Maktua, temporarily halting their attack. But Maktua were resourceful. The Maktua soon learned they could establish psychic links with their Shadow Matoran slaves, and they began carrying Matoran on their backs to act as eyes during battle. Kirop was chosen to mount the disgraced scientist Chriox, and the two would often fly into battle.

More help would soon arrive. The six Toa Nuva, equipped with Adaptive Armor, had been sent to Karda Nui to finally reawaken Mata Nui. While there they protected the Av-Matoran from the Makuta onslaught. At one point Kirop was captured by the Toa and imprisoned in their shelter. Kirop overheard the Toa's plans form the next room. They claimed to know the location of the Maktua's hive and where planning an assault! Kirop quickly escaped his prison and rushed off to warn his master.

In truth, the Toa had no idea where the hive was and had purposefully left an escape route in Kirop's cell. After Kirop "escaped" they stayed on his trail until they reached the Maktua hive... Then broke it off the ceiling and cast it into the swamp!

Mutran's precious lab was now nothing but a pile of rubble sinking into mud. His vats of Shadow Leeches decimated, his equipment broken, his ch

Mutran's precious lab was now nothing but a pile of rubble sinking into mud. His vats of Shadow Leeches decimated, his equipment broken, his chemicals all out of order! He set to work trying to rebuild some sort of testing center to keep the mission alive... but in order to do so out in the open he would need a guardian.

Mutran figured you couldn't beat the classics, so he cracked out an old recipe for the Klakk. Klakk were midsized bat Rahi, equipped with powerful sonic scream abilities, often used to guard Makuta lairs. Shortly after it was finished, however, this Klakk broke free from containment and blasted it's creators, soaring off into the wilds. Mutran sent his assistant Vican after the beast to retrieve it.

But Vican had other plans. The sonic scream from the Klakk had an unusual effect on the Matoran... it had broken the shadow barrier! The Shadow Leech's mind control had been broken and Vican was free from the Makuta's grasp. Vican quickly warned Takanuva, Toa of Twilight, of this discovery, and the two set off to free the other Shadow Matoran.

Kirop was cured by the Klakk's scream. As the Toa Nuva prepared to turn the Karda Nui generator back on and reawaken Mata Nui, they shuttled the cured Av-Matoran out of the chamber. These Matoran fled north and settled down in the Toa Nuva's home city of Metru Nui.

Eventually Kirop would leave the Great Sprit Robot after the machine was destroyed at Journey's End. He became one of the many inhabitants of New Atero on the reformed world of Shperus Magna.

As an Av-Matoran Kirop could fire blasts of light from his hands, blasts of shadow as a Shadow Matoran. As an Av-Matoran Kirop wore a powerless Kanohi Pakari, the Mask of Strength. This was replaced by a powerless Kanohi Shelek, the Mask of Silence, while under Makuta control. As a Shadow Matoran Kirop took flight on a pair of bat-like wings and channeled his dark power through sickle like claws.

@MrGurt said:
"crazy that there were 12 more Bionicle sets that year than there were Star Wars! "

2008 and 2009 where massive years for BIONICLE, the former because it was the finale of the Aqua Magna "half" of the story.

I always knew that Imperial Terror Troopers were part of the Bionicle Canon.

@MrGurt said:
"crazy that there were 12 more Bionicle sets that year than there were Star Wars! "

Crazy to think about how there was a time when Star Wars wasn't LEGO's most profitable theme....

This just further reinforces my belief that current movies coming out is what's selling Star Wars sets. 2008 had the Clone Wars TV Show, but no new movies came out until 2015. Guess what happened for LEGO between 2006-2015.... We got dozens upon dozens of original themes, including four new original Space themes. Guess what happened post 2015? Most original themes died out yet again.

@LegoDavid said:
" @MrGurt said:
"crazy that there were 12 more Bionicle sets that year than there were Star Wars! "

Crazy to think about how there was a time when Star Wars wasn't LEGO's most profitable theme....

This just further reinforces my belief that current movies coming out is what's selling Star Wars sets. 2008 had the Clone Wars TV Show, but no new movies came out until 2015. Guess what happened for LEGO between 2006-2015.... We got dozens upon dozens of original themes, including four new original Space themes. Guess what happened post 2015? Most original themes died out yet again. "

In _Brick by Brick_ they corroborate that in the early 2000s this was definitely the case. One of the reasons lego almost went bankrupt in 2003 was that there was no Star Wars movie in 2003-2004. They quickly learned that such a license is a lot less profitable without a direct tie-in. This was also the case in 2001. But in 2003 both Harry Potter and Star Wars were in-between films.

Bionicle in the contrary did better precisely because it was their own. In 2003 it even got a boost because of the Miramax direct-to-video film Bionicle: The Mask of Light. But even in the other years it went strong. Of course it eventually faced a gradual decline until they thought they had to make a soft reboot in 2009. It ended in 2010 with people inside the company having to advocate for even making a final send-off wave. It lasted 10 years though...

As for this set. I own it but have been on the verge of selling it for awhile because of the brittle joints and general lack of rebuildability because of that. But seeing it here made me realize how much it means to me. I got it at Legoland Billund in 2008, so it has a special place in my heart.