)
You can't control two or more legendary creatures _*with the same name._* You can control both Twilight and Spike simultaneously without any issue, but if you try to double up on either, the game will force you to put all but one of them into their owners' graveyards. Heck, since the name has to match _*exactly,_* you can control both Twilight the Cunning and "[Princess Twilight Sparkle":](https://derpibooru.org/images/2159237) at the same time without issue.