Due to a stroke of catastrophically bad luck, you've somehow attracted the attention of Larloch, the powerful lich known as the Shadow King of Warlock's Crypt, and while you often feel like you're being watched (and will almost certainly end up involved in a nefarious scheme or horrific experiment), you also benefit from Larloch's unwillingness to share his toys.
You always have the spell "Protection From Evil and Good" prepared, and may cast it on yourself, once per long rest, without using a spell slot and without any components. When cast in this way, you are immune to the divination spells of liches other than Larloch and are invisible to them (this invisibility is not pierced by Truesight) until the spell ends.