Shattered Shackle

Shattered Shackle is a Keepsake that increases the damage dealt by Zagreus' Attack, Special and Cast when they are not empowered by a Boon. It is obtained by giving Sisyphus a gift of Nectar when he is found in the dungeon. Its effects can be enhanced by clearing enough encounters with the keepsake equipped.

Unequipping the Shattered Shackle between levels will remove the damage bonus to abilities not enhanced by a Boon.

Effects
Your Attack, Special, and Cast each deal damage while not empowered by a Boon.

Bond Message
From Sisyphus; you share a Rock-Solid Bond

If he can hoist a boulder on his own, he knows he can be of some support.

Note

 * In order for the Shackle's bonuses to work, no Boons must be equipped in the Attack, Special or Cast slots. Chaos boons, Daedalus weapon upgrades and Hermes boons do not affect the bonuses you get from the Shackle, nor do defensive boons, dash boons or miscellaneous boons from gods. In addition, assignment of a boon to a given slot does not void the bonus from the other slots (so for example, if you're forced to take a Cast boon, it does not affect Attack and Special).