This spell can only be cast by those who carry a Firal Descendent's Mark on their body.   For the duration of the spell, your blood glows and omits a turquoise light. Any messages written using your blood will keep glowing until the end of the spell. Once the spell is finished, any spilled blood becomes invisible.   Your body sheds a dim turqoise light in a 10-foot radius. The light emitted by you with light up any previously written messages.   As a bonus action on your turn, you can end the spell.