Board Thread:Off Topic/@comment-25405817-20160511154306/@comment-25405817-20160512182100

I agree with Cyrania de Bergerac here. The "Character from X is throw into Y" format only works if the precense of this character has an impact on the events of the original story.

Though not exactly a crossover, "The Flashpoint Paradox" explains it better (SPOILER WARNING):

"When you break the sound barrier, there's a sonic boom. You broke the time barrier, Barry. Time Boom. It shook the entire world. Things are very different now."

It bears to reason that the addition of a character not originally in the story should have some wide-scale consequences.