Make her his girlfriend

"Emerald," Duke said, remembering what Glynda said. "First and foremost, you'll forget all about this hypnosis session. You'll think there was glitter on your forehead and I got rid of it."

"Yes," Emerald droned.

"Next, when you wake up, you'll be so utterly attracted to me. In fact, you think we've been dating for a bit. However long is up to you. You'll be loving and doting towards me, and be totally for me having a harem if it means I'm happy. Understand?"

"Yes..." Emerald droned.

"Any time I ask you to hang out, you'll prioritize me over Cinder or Neo. Let them sort things out themselves," Duke continued, wanting to help Emerald out. "And...you love the feeling of my dick. Whether in your ass, pussy, mouth, or between your tits, my dick makes you cum like crazy."