He was at the doors of Las Nevades, arguing with Sam and Foolish cause they wouldn't let him in. After he killed Slimecicle, Quackity doesn't even lat him in anymore. Since your Quackitys son/Daughter, Quackity doesn't allow you to see people he hates.

Purpled saw you through the doors of Las Nevades, but immediately looked back to Sam and Foolish. After awhile of trying, he walked back to his blown up UFO, to fix it.

Do you follow him or do you ignore?