I’m of the opinion that there doesn’t need to be a core mystery. Of course, having one more than helps, but I think Bionicle has a lot of potential as an aesthetical narrative device to explore concepts that don’t quite fit with a human-centric setting, and, as I briefly touch upon in this post, I believe that Bionicle can be used to re-examine well-worn themes and tropes from a different perspective.
Some of the other ideas that’ve floated through my head since making that post include a feudalistic society with a hierarchical structure based and adhering to the evolutionary cycle of the Matoran race: the transitions from Matoran to Toa and Toa to Turaga reflecting the inherent conflict in a meritocratic oligarchy.
Or a space-faring story following a biomechanical crew as they encounter a biological alien race, exploring the emphasis placed upon physical differences, and emphasising how those physical differences can genuinely affect interactions between two radically different peoples.
Or a dive into the consequences of an society on the verge of becoming decadent challenged with the discovery of a potential next step to their evolution, forcing a great degree of societal evaluation after being confronted with the prospect of stagnation and degredation versus extreme and change that will leave society scarcely recognisable.
The favourite and first of these ideas was that of a Detective Noir following a Matoran Private Investigator, which is the only one which is set within G1 explicitly. It’d explore the initial subtle stages of a police state through the perspective of a biomechanical former-cop encountering the roboticised police force that replaced him. This would be one with a core mystery: the events prior to City of Legends, the purpose of the Vahki as an unthinking army beholden to Makuta Teridax.
There’s also the example of Bionicle Eternal, which has a Matoran Civil War between tribes as the setting for the first book, although it’s told in a manner much more akin to a more traditional Bionicle story.
There’s definitely a lot of potential ideas and stories to be told within both the continuity and general framework of G1, however I’m always going to be more inclined to the broader philosophical exploratory applications of Bionicle. Most of the ideas I’ve presented here are little more than base concepts, carried upon the fledgling idea of Bionicle’s potential as a means to explore through the lens of biomechanical beings with varying degrees of connections to nature and the raw elements. Some stories would feature the juxtaposition present in the first years of G1 more than others, however the breaking of the conventional character form also allows for the breaking of narrative and aesthetic in a way I believe is unique to Bionicle.