Obviously I have a bias toward brain drain, so perhaps a scenario in which a victim has their brains literally sucked out of their head by a straw/tentacle/etc.

Hmmm :3

And why not two jock wolf / dog roommates who would be hypnotized by a nerd (mouse, fox for example) using necklaces, music or a screen?

Quite interesting. Small top big bot huh :3

^^

I like hypno via helmets and masks. hypnosis via pods or vacbeds also

Hmm more tools :3

do you take ideas that could not fit in one image ?

Any idea would do. It's for practicing

I don't know if this might interest you but I suggest: A lion watches his favorite series (the lion king) with simba, scar .. and buys a limited edition bonus dvd where scar will hypnotize him with his body and a mantra to come join simba and his male lion pride