Christian Faber was kind enough to share a piece of concept BIONICLE artwork with me over email:

Something else that might be interesting is, he'll soon be launching a website, entirely dedicated to his work with LEGO during the past 25 years. As I suspected, he was also involved in the making of the Slizer/Throwbots series, so it's quite possible that we may finally obtain some form of official canon for the guys.