Within Bionicle, the story noticeably turned a shade darker from '04 to '05, and with the advent of the online serials in '07, it also became Bloodier and Gorier. So much, in fact, it made the initial years look like a kindergarten play in comparison. A good deal of this stuff LEGO would never have allowed the writer to publish when the theme first started.
Fanfics and forum Role playing Games based on BIONICLE will often make the characters take on more human traits compared to their 85% metal, 15% muscle/lung tissue that is canon. While the primary reason by that it's easier to Write What You Know, the addition of human aspects also means that fanfic characters suddenly have more detailed descriptions of such things as pain, bleeding, etc.
Everything with Matoro and the Barraki saga basically slaps you in the face if the Piraka saga hasn't already. Not only do we get a downer ending, in another serial we're showned exactly what would have happened if Matoro never put the mask on. the universe dies, and Matoro is labeled a coward and a pariah. Everyone also is now deprived of a home because the universe is crumbling, and Matoro only redeems himself when he sacrifices his life again to save the village. The guy just can't catch a break