Pact

9th level abjuration (ritual)
Casting Time: 1 hour
Range: 60 feet
Components: V S M (a vial of blood from a willing creature)
Duration: Indefinite
Classes: Shaman
You spend an hour chanting ancient words from Shaman long dead, and meditating on terms negotiated with another creature willingly participating in this ritual. When complete, you grant the other creature one level in Warlock and become their patron. The creature's pact type is Undying. In exchange, you may call upon the creature to undertake missions and do your bidding. Should the creature refuse, the pact is bound and they cannot increase in power from this ritual until they complete the task you gave them. Should you die, the creature can continue to gain power. If the creature dies, you permanently gain a spell slot in the spell level equal to 1/2 of the creature's warlock level. If you are dead when the creature dies, you have a 50% chance to return to life instead of gaining a spell slot.
If you have at least 10 creatures that have formed a pact with you, your race becomes undead. For every creature with a pact to you after 10, you gain an additional totem, cantrip, or spell slot. Spell slots gained are equal to the total number of creatures you make a pact with -10.
Should you reach 25 or more creatures with a pact to you, you may sacrifice 5 of these creatures to grant yourself automatic success on death saving throws, gaining 50 hit points.