While attuned to this purplish gemstone, you can cast the spell Etherealness targeting only yourself, except the duration is reduced to 1 minute. Once you have used Zilla's Heartstone this way, it cannot be used again until the next dawn. Each time you return to the material plane after the effect has ended, roll a d20. On a 1, the Heartstone shatters into multiple pieces and loses all of its magic. 

Notes: Requires attunement by someone who has killed Zilla Soulcatcher