Blessing of the Old Blood

There is deep magic in the noble bloodline of your family. On your turn as an action, you may deal 1d8 damage to yourself to claim the ground you fight upon and bless those who fight beside you. For one minute an ethereal banner appears which grants the effects of the bless spell upon up to four willing creatures of your choice within 30 ft of the banner. 

If a creature blessed in this way deals damage to you, the effect immediately ends on that creature and they take 2d6 necrotic damage.

Once you have used this ability a number of times equal to your proficiency modifier you must finish a long rest before you can use it again.