A grim figure of authority who battled to keep the artistic, freedom-loving peoples of his home island in some semblance of order.
Xalos is a character from the Cyclic Plane Storyline. Stuff in bold is related to that storyline.
Xalos was created, as most matoran are, by the machinery of the Matoran Universe itself. He lived on the Tren Krom Peninsula and moved to a new island after it was created off the Southeastern coast by the first Onu-Nui, Serpes. Makuta Raximoras, assigned to the island, later upgraded Xalos’ body, along with many other matoran.
After the Brotherhood of Makuta sold the island to Poliaz in return for his Toa Power, Raximoras left and Poliaz became the new ruler. Naming the island after himself and with his vortixx viceroy Vanembar by his side, Poliaz also promoted Xalos to captain of the guard of the island.
Xalos became very good friends with Gratigan, but was otherwise a very stern, humourless and pragmatic guard captain who spent nearly all his time working. As the city’s population and influence grew, and gangs like the Black Delta sprouted up, his job became increasingly difficult. Poliaz and Vanembar often didn’t listen to him; they were often more concerned with finding more rare masks and artefacts to add to the vaults under the island.
After Lizena was killed by a Kanohi Dragon Xalos, along with Gratigan, Soleku, Orabmar and Gringat, became Toa in a risky procedure that exposed them to Energised Protodermis. Xalos led the Toa Vanembar.
There we go! My oldest surviving MOC alongside my newest. 
I swapped the bulbs in Umbra’s weapons to get Xalos’ ice axe. In the lore it was mainly a badge of office kinda thing (just like the shoulder sash), but it could freeze criminals in place too.
The buttons and chain and sash are all based off some designs of uniforms from fantasy type games. Poliaz itself was kinda rennaisance-ish with a lot of baroque styling and more mediterranean type culture.
Xalos is gay. For matoran in my storyline that’s not unusual, but hey, trivia.
Major inspiration for Xalos comes from Commander Vimes from the Discworld series of books by Sir Terry Pratchett, though the characters aren’t too alike in terms of personality. Another source is Javert from Les Miserables.
Here’s some previous versions:
2010: 
2009: 
