Hythonia as a Mythic Encounter
Hythonia serves as a potent threat against even high-level characters, but you can increase the challenge by using the Shed Skin trait. When this happens, Hythonia heals many of her wounds and slips away from danger, and then she can choose one of her mythic actions when she uses a legendary action.
You might foreshadow Hythonia using her mythic trait by describing her skin cracking and turning pale as she suffers wounds. Read or paraphrase the following text when Hythonia finally uses her Shed Skin trait:
The medusa’s skin cracks, turns a lifeless gray, and shatters! The monster crumbles to dust—but what clatters to the ground isn’t scale and bone, but hollow stone. The sound of rippling coils precedes the medusa rising up anew, the last of her shed skin dropping away, revealing glistening, unscarred scales.
Fighting Hythonia as a mythic encounter is equivalent to taking on two challenge rating 17 creatures in one encounter. Award a party 36,000 XP for defeating Hythonia after she uses Shed Skin.