#echothevessel

In Of Spiders and Serpents, the Vessels are basically Wyrm corpses that were reanimated by Void, and then given shape by twisted roots. Hollow was no exception, but after centuries upon centuries of being locked away and desperately trying to hold back Radiance, its roots began to fall apart from the strain. It can barely hold its form now, only managing to stay in a coherent Wyrmlike shape through the sheer force of a will it was never supposed to have.

Hollow's chest is also full of semi-dormant Dreamlight boils, which flare up if it resists Radiance too long, reminding it of who's really in control. Radiance uses Hollow's body as a puppet during its fight with Ghost—and in the brief moments where Hollow regains control, it tries to end the fight itself, stabbing at the space its heart would have been, were it ever alive to have one.