Why did the Kraang need to perfect the mutagen?
 

Perfected mutagen makes power cells, right? So why did they need mutagen if they could bring the power cells with the one Power Cell that Leatherhead stole.

I'm not sure how you missed it but no, that was not the reason.

The reason they needed a perfect mutagen was so they could make Earth as similar to Dimension X as possible, if they didn't perfect it then all they would have were random monsters.

Didn't Kraang Prime attempt to mutate the earth with the powers he (it?) (she?) got from April?

April is a human whose maternal family had the DNA strand needed to perfect the mutagen. And everyone from her maternal great-grandfather onward had been experimented on to refine that piece of human DNA needed.

Either because of the experimentation performed on April's mother or while April herself was in utero. April is a half human/half kraang hybrid which makes her the key to perfecting the mutagen.

Basically Mutagen was turning people and things into anthropomorphic creatures, but they wanted it to essentially terraform the Earth into another Dimension X.

I am not sure perfected mutagen makes power cells. Power cells are completely different.

Then what were those crystals in Dimension x?

The story of Nick Toon April is such a mess, I lost track a long time ago.

They're just crystals, maybe you're looking too much into it.

But when Mikey grabbed a crystal in "Into Dimension X", Donnie used it to power the turtle mech. Like the Power Cell.

By the way, how did you get that image there?

I thought he just broke off a piece of a bangrock to detonate the Kraang base.

Have you seen The Kraang Conspiracy, Into Dimension X, and The Invasion?

The crystal is the power cell. And if you referred to the gif under my post, it's a signature.

You mean "a" power cell.

Yeah. Did I make a grammar error?