Is there a point of doing something harder than turn 5?

[Alkimi]

Just to clarify, Twintania is not hard.

Sure, once you've beaten it once, you can down it easily. Maybe 2 or 3 attempts for your next couple and then pretty much 1/1 from then on.

But you make it sound as if players can clear Turn 4 for the first time and then just beat Turn 5 in one sitting. You can watch all the videos and read all the guides you want, but when you start out on Twintania you're going to wipe a hell of a lot while you get used to her mechanics.