[Set] (This card remains on the field.) [Act] Pay 4 gauge. If you do, call one Class 2 or less X-Cell Monster with "Umbral Walker" in its card name from your extra deck in [Rest] without paying the [Tribute] in its [Call Cost]. Then, at the start of your turn, destroy it. This ability can only be used once per turn. (This call is not treated as a X-Cell Call.) You can only [Set] one "Eclipse of the Undead" on your field.