Zep's Abyssal Shroud

You cloak yourself with the shadows of the deep abyss, letting you vanish from even perfect sight. Until the end of your next turn, you have the Invisible condition until the spell ends. While invisible this way, creatures have disadvantage on any checks made relating to locating you, and creatures with truesight cannot see you.

Devil's Deal. As a bonus action while casting the spell, you can extend the duration to 1 minute. At the end of this spell's duration, if it was extended this way, you are vulnerable to all damage for 1 minute.