Takanuva

In an alternate reality dubbed "Takanuva's World", Blackout had taken over the Matoran Universe. In a last-ditch attempt to stop him, Takanuva engaged the Makuta in battle, but was impaled with the Master Sword and killed.

Trivia
Takanuva's inclusion in BZPB is somewhat confusing. Takanuva was first mentioned in Dusk and Dawn, a BZPB story that takes place after the events of Dark Mirror, an official BIONICLE serial. It is implied that the Takanuva mentioned in Dusk and Dawn was the same one who appeared in Dark Mirror, meaning that he would have originated from the BIONICLE universe. However, in BZPB, the BIONICLE universe was merged with the Original Universe, so the BZPB Takanuva would likely have originated from the OU. If this is the case, OU Takanuva would not have had the same reason to cross dimensions as BIONICLE Takanuva did (in BIONICLE, his mission was to warn the Toa Nuva of the Energy Storms in Karda Nui). So, if OU Takanuva really did go to the DMU and kill DM Tuyet, that opens up a whole new can of worms...

As if that wasn't enough of a headache, it is unclear whether or not the Takanuva who fought the alternate Blackout on "Takanuva's World" is the original Takanuva, or a Takanuva originating from "Takanuva's World". Since Takanuva is an cross-dimensional traveller, it could easily be either.