Scale of Will (5e Equipment)
From D&D Wiki
Wondrous item, unique
This scale must be embedded into a creature's hand at or before birth through a painful and burning process in order to work. Doing so bonds the creature to dragonkind for life, and blesses it with unfathomable willpower that must be unlocked throughout the creature's life.
Dormant. While the Scale of Will is embedded in your hand, you and the dragon you're bonded to are tied together, such that neither are likely to stay dead unless both die. If at any point you or it dies, the scale ceases to function, but the body doesn't begin decaying until the other creature dies (Effectively halting the timer on bringing the creature back to life). If both creatures are brought back to life, the scale begins to function again. Additionally, you can cast spells that would otherwise require being a dragon to cast, though you must still learn the spell and meet any other requirements to do so.
Awakened. When the Scale of Will reaches an awakened state, you recover all of your hit points and spellslots, and it gains the following properties:
You can attempt to cast a spell you don't know. When you do so, you must cast the spell at its base level, provide all the required components and spellslot, can't cast it as a ritual spell, and make an arcana check with a DC of 10 + the spell's level (or 10, if the spell is a cantrip). If you succeed the check, you can cast the spell, but take necrotic damage equal to 10 X the spell's level (or 10, if the spell is a cantrip). This necrotic damage cannot be reduced or avoided in any way. If you fail the check, you still take the damage, but the spell is wasted. Pass or fail, the material components (If any) and spellslot are expended even if they otherwise wouldn't be (Including using a focus), and the Scale of Will reverts to a dormant state until awakened again.
Exalted. When the Scale of Will reaches an exalted state, you recover all of your hit points and spellslots, and it gains the following properties:
When a creature rolls a 1 on a saving throw against your spells, they automatically fail the saving throw, and can't use any features, traits, or effects, such as Legendary Resistance, to succeed on the saving throw. If the spell deals damage, the damage dice are doubled. Additionally, if you use the Scale of Will's Awakened property, the item reverts to its awakened state instead of its dormant state until exalted again.