Board Thread:Fun and Games/@comment-35757757-20190903220313/@comment-35757757-20190908025256

Could you please explain this part for me?

“He noticed Dream, filled with negative emotions (Wanting to be killed by Nightmare) and decided he was the most optimistic person to choose. He contacted him while he was sleeping, but Dream thought it was a dream and went back to sleep. Then Cide decided to kill everyone by possessing CF Flowey.“