On death, Isaac's ghost is chained to his dead body and he can continue to fight with 1/2 of a heart, returning to life after 10 seconds. Must be recharged by picking up a soul heart.
Quote
"Unfinished business"
Effects
Upon death, Isaac turns into a ghost that is linked to Isaac's dead body, and can continue fighting with 1/2 of a heart. 10 seconds after this effect occurs, Isaac comes back to life.
Isaac has flight and spectral tears while in ghost form.
After this effect occurs, Spirit Shackles cannot activate again until Isaac picks up a soul heart. Soul hearts that are used to charge Spirit Shackles will not be added to Isaac's health.