It is the newborn goddess and she feels unstoppable 

Fionna: HA HA HA HA I am God. The power the absolute power I can do Anything I want HA HA HA HA HA

Ellen is standing with tears in her eyes as she begins to realise what she has allowed to happen the other girls are behing her kneeling on the ground in prostration. Ellen cries out to fionna

Ellen: please fionna take of that mask it is driving you crazy 

Fionna looks toward Ellen with a giant smirk of disgust her eyes burning with her greatly amplifyed desires her body heaving with the raw power she had now taken as her own

fionna:you pathetic little whore you have no idea of what I have gained in these past few minutes or what I still have yet to achieve this power that can make me into anything or let me do anything but it does have its limitations. I can now Go Anywhere and take whatever I want who could stop me.

Ellen is absoutly terrifyed she dosent understand what fionna is talking about and asks timidly what do you you mean

Fionna: HA HA HA HA HA I AM AOUT TO BECOME ONE WITH THE MOST POWERFUL OBJECTS SCATTERED THROUGHOUT FICTION AND THEN I WILL TRUELY BECOME THE GOLDEN GODQUEEN THAT I HAVE FANTASISED MY ENTIRE LIFE ALL CREATION WILL SOON KNEEL TO ME HA HA HA HA HA