It's not mind control goo, it's... The Thing? Ikeda sure loves his horror movies, haha!
Also, Inner and Outer Moka are really one and the same, aren't they?
As in back during the first season, Outer Moka tried to do the exact same thing in a bid to save Tsukune.
In the end, if saving him meant she(they) had to grovel at her(their) enemy's feet, she(they) would gladly do so.
Also outlining how Moka and Tsukune are practically made for each other, kek.
Lastly, this is also starting to rub itself onto another theory of mine. That is, if it weren't for the Shinso blood, Inner Moka would have naturally grown to look like Outer Moka.
Also implying that the Rosario wasn't simply sealing the power of her blood, but also the effects it had on her growing up.
...Thinking about it, I'm probably just pointing out the obvious but eh whatever. ¯\_(ツ)_/¯