Wyrmstone

Wyrmstones are the crystallized essence of a slain Wyrm, as the being cannot truly die, they leave behind the object when their body has been destroyed. They resemble a dragon's eye, the color varying upon the elemental affinity associated with the being, and or the color of its eyes in the original body.

Wyrmstones are indestructible, and cannot be destroyed unlike Dragonstones, their lesser variant which can be. The former Wyrm will attract those who seek power, giving off a large alluring aura until eventually finding a worthy host. It slowly corrodes the body and will of its host, transforming them into a more draconic form over time. Eventually, the mind will break, their consciousness devoured by the Wyrm dwelling within the stone, and through the death of the host the being is reborn once again. It is possible to resist the will of the creature, or overpower it and obtain the body and power of the Wyrm without losing ones self; however, this requires an enormous amount of willpower, the likes barely any living being can manage. Only two instances of a mortal overcoming the will of a Wyrm has ever occurred: Seraiya with The Eye of Tiamat, and Ryujin with the Eye of Bahamut.

Wyrmstones can form powerful weapons around them, in the shape of what the wielder wishes it to be, though they are limited depending on the age of the stone and the Wyrm's original power. This is also what determines the size of the stone in death.

Once attached to a host, they will find it impossible to part with, feeling as if they're incredibly exhausted, or as if they're parting with a part of themselves. It can be likened to the withdrawals of addictive substances.