User blog comment:Deathkin12/Teaser Theory/@comment-5297851-20160101143000

There's been a development to this, which further supports my theory. Apparently, when a new teaser is shown, the last one is taken down (Zed's was removed when Sona's was revealed) which gave me the idea, if he/she really does play with the dreams of the champions, then she could only enter a dream one at a time, which would cause the others to wake up. And if this mean he/she would receive a sleep inducing spell, then he/she could only put one unit to sleep at a time.