Scariest hack ever made...
Use a Max Repel while in the Berry Forest
Don't you think you have more serious issues to be focusing on right now? (Open the Trainer Card at any time after losing to Hypno)
Talk to every interactable NPC (besides the healer) in the first section of Hypno's cave in one session
Pass through the dark room in one session without defeating any of the humans
Defeat Hypno in front of the Pokemon Tower
"Oh, little children, you weren't clever- now you shall stay with me forever..."
Get the "Good Ending"