Yes, we all know Bionicle ended.
But that doesn't mean  that there isn't a room for no more stories and chronicles. I mean one of the reasons Lego created Bionicle was to have a serious desent story!
-
So this is one way to continue Bionicle, by returning to the stories that were officially told and use your imagination to fill it in.
Or
Create a  whole different story, start a New Beginning.
We all know the mask of dimensional gates right?
What if there is a dimensional war, in Dark mirror and other dimensions,  the plot was different.
Maybe set up a story for other dimensions. Or like I said the clash of Dimensions, There are full of possibilities on how things should happen.

Also we need a new villain, It was mostly around Teridax. But now that he is dead, how about a new race that is trying to conquer or destroy a universe. personally I was thinking of a villain witha  mix of light and shadow (like takanuva) but has this crazy belief that everything should revolve around order and balance, and no mix.

Also how a bout a new breed of heroes, new toa teams, glatorian, maybe makuta joins for the battle for the good (i don't know if the liquid that creates makuta is destroyed or not).

Anyways, who ever reads this journal I hope they consider this carefully.