I sort of find all sleepy fantasies/limpplay/drunken/passed out fantasies arousing. Each scenario offers different things that can be exciting to me.
Whether a struggle before being/putting them out. Putting up that fight, in hopes of winning and getting away until the sensation of drowsiness takes over nipping the fight out and leaving the victim absolutely helpless.
Stalk/hunt is probably a favorite though. Stalk/hunt scenario of anything can be more enticing due to a bit more of a primal nature that comes across in the beginning/during the chase to me. All up to that moment when caught, adrenaline rushing through the system mixed with fear then realizing it’s too late, had been caught as the body begins to weaken and running is no longer an option while fighting against the affects.
And of course, the simple surrender in hopes that it would be better, with a chance of things going easy and light, or not even knowing what was happening and being completely oblivious and it not clicking until it was too late.
Meh, it can all be sexeh fantasies