After narrowly escaping from the Void in the Great Unknown, Sonic discovers a strange ring that he brings back to Sally Acorn to investigate. After translating a few words on it, the ring activates a spell that envelops her & Bunnie Rabbot; dragging them back out to the Void in the Great Unknown. The ring was actually a trap laid out by the Chimera-like wizard Ixis Naugus (here simply reffered to as "Naugus") in an attempt to capture Sonic's friends so that he could lure the Blue Blur to him in hopes of using his hyper speed powers to escape. After using his magic to probe Sally & Bunnie's minds, he takes a moment to explain how he was the one who originally found the Void in the first place, and how Robotnik betrayed him & sealed him inside potentially forever. He then uses his magic to seal Bunnie & Sally inside of large crystals to keep them in place until Sonic arrives; afterwhich he de-crystallizes them to show the hedgehog that they're alright.
"Sonic the Hedgehog", otherwise known by fans as "Sonic SatAM", was an American animated television series based on the Sonic the Hedgehog video game series. It is a cult classic amongst Sonic & cartoon fans, and was eventually used as major inspiration for the currently ongoing Archie Comics series of the same name. Created by Len Jason and produced by DiC Entertainment in association with SEGA of America, the series produced 26 episodes spanned across two seasons (with a third season planned, but sadly cancelled): originally airing on ABC from September 1993 until December 1994.
Unless you count Robotnik's "Robotization Process", which was his main way of taking over Mobius; enslaving the people of the world and a major plot point of the series, "The Void" (which originally aired on October 29, 1994) is the only episode in the series to feature ASFR content. It is interesting to note, though, that the crystallization spell Naugus uses in this episode ends up becoming one of his signature spells in the Archie Sonic publication; allowing him to turn anything he uses it on (organic or mechanical) into solid crystal. Sadly, this power is underutilized in the comic as the only ones whom are ever fully crystalized by his magic across the 250+ comics (not including spinoffs & side series), to the editor's current knowledge, is (former) King Maximillion Acorn and (former) Warlord Kodos (though Bunnie Rabbot DID get partially crystalized once, which resulted in her derobotization once she was restored), and the individual isn't completely immobilized by it: rather turned into a living crystal golem that can then be controlled by Naugus.