Moonblade

A moonblade is an hereditary magical sword passed down in elf lineages.

Description
Each moonblade is passed down from parent to child, but only a worthy heir will be able to wield the moonblade. Any unworthy bearer who draws it will die, thus making the inheritance a highly risky endeavour. It also cannot be wielded by anybody other than the rightful heir. Each wielder may contribute a power to the sword, which will be absorbed through the stone in the blade's hilt, a moonstone. However, the wielder cannot be separated from it for any length of time and expect to live. Each moonblade is unique, as the powers given to it are different.