Fuck! What's wrong with me?" You tell yourself. You sigh and start following Duke's footprints. You follow the trail for about a hundred yards. You see Duke up ahead, he doesn't look well. He is stumbling around looking ill. You follow for a bit then he dry heaves and falls over.
You run up to him. He is passed out cold. He must be in some sort of dream. His eyes are closed but you see they are moving rapidly. His legs twitch as though he was running and he quietly barks and growls. You touch his brow. He's burning up. He is so vulnerable right now. You get a wicked idea. You could kill him right here.
He's laying on his side with his neck exposed. You could just sharpen a stick and plunge it into his neck. It would be easy. Maybe he comes out of this dream a good dog or maybe he comes out worse. Can you really take that risk? What if he wakes up and kills you, or makes you take him to Moki? This would be the perfect time to end it all. You look around and see a broken limb. You run over and gnaw on the end until it's sharpened to a fine point. You touch the end, this would do the trick.
You walk back over to Duke, he is still unconscious. You've never killed anything before but you have to do this. You can't risk your own life or Moki's and if there was any Pokémon that deserves to die, it would be Duke. You lift up the stake over his throat. He twitches in his dream. Do you kill Duke?