Making character Palette swap when transforming? Transformation Help

[AmaaDivine]

Hi there! I want my character to transform, but using the Player_Attack_Darkness animation, and simply changing her horn from white to black, and her eyes glow orange. The to use the "dying" animation when she comes out of the transformation. What kind of code would I use

I also would like to add a custom roar when the transformation happens.

Perhaps have the ability to roar and cause other to flee