You can cast raise dead once without expending a spell slot
or material components. A creature returned to life when you cast the spell in this way is charmed by you, you know if it ever
dies, and at any point while it lives you can use your action to cause the creature to die instantly. The creature's soul is
aware of the nature of this effect before it chooses to return.

Additionally, when you cast the spell, you can offer the creature your choice of one of the following benefits, which it gains if it returns to life:

• The creature learns a warlock cantrip you know.
• The creature learns one 1st-level spell from the warlock spell list that you know, and can cast it once at its lowest level without expending a spell slot. Once it does so, it mush finish a long rest before it can cast it again.
• The creature learns one eldritch invocation that you
  know, so long as it doesn't have a prerequisite.

You choose what the creature learns, and it uses
Charisma as its spellcasting ability for the choice if
it requires one.

Once you cast the spell in this way, you can't do
so again until you finish a long rest. You can't cast
raise dead in this way on the same creature more
than once.