So, in a campaign I just joined, my character is secretly going to be trying to kidnap one of the other PC's much later in the game, to use as a sacrifice for a pact of demons. She's role-playing to become more and more paranoid of the party. I plan on casting Seeming on all but mine her characters to make them appear like demons or something while they're sleeping, and then get her to teleport with me to a rune circle that the demons designated. The spell reads "You make any amount of creatures you can see look different until the spell ends or until you use your action to dismiss it...If a creature is unwilling, it must pass a Charisma save to be unaffected."
I was wondering. Would they still have to make the Charisma save even though they're sleeping? I mean, technically they aren't unwilling, but it's not consensual.