Death's Doorman

Frequent visits to Death’s Realm has gifted you with the ability to stand as a gatekeeper for Death itself, granting you the ability to deny those you wish for from walking past.

Soul Ward:
You may grant a blessing onto a number of willing creatures equal to your proficiency bonus per day in order to ward them against death. A creature cannot bear more than one Soul Ward per long rest and it lasts until your next long rest.
Should a warded creature reach 0 Hit Points or die, it is immediately set to its maximum Hit Points instead and loses the ward.

Denying Death another soul this way comes with a risk.
When a warded creature loses the Soul Ward, they have to choose between taking either a failed death save, or one point of exhaustion. Accumulated failed death saves and points of exhaustion can only be cleansed via a long rest and if the number of failed death saves reaches 3, they die.