Bionicle 3: Web of Shadows (2005)
The Web of Shadows concerns the return of the heroic Toa to Metru Nui. There, they find an old enemy has overtaken the great city with the help of Visorak--robotic spiders that can quickly encase anything or anybody in near-indestructible webs. The Toa undergo a bizarre metamorphosis while sealed within strange cocoons, and emerge as clunky-looking machines made up of mismatched parts. Though horrified, they find that they also possess some new powers, which prove essential for their subsequent journey to restore Metru Nui--and themselves. This delightful Bionicle installment is probably easily accessible for any viewer unfamiliar with the series to date.