PT Is Ian's portrayal of Sidious a bit over the top after killing Windu?

I thought that the usage of the deeper and more dramatic tone was permissible in that scene because he is literally making a pact with the Devil(Sidious).

The hoarser tone almost symbolizes the Devil as an animal gloating in its kill: the fact that it has seduced the most powerful being into the Dark Side. Just this once, the pure evil that is Sidious is seen showcasing the rawer, more bloodthirsty and feral emotions of the dark side before subsiding into his clipped, sleek tone.

Also, if one is to take Sidious as a metaphor for all the darkness in the galaxy, then the magnification in the voice could represent the colossal increase in the darkness that would engulf the galaxy with Sidious now in absolute control and the Chosen One having fallen.

 

Yeah, Palpatine and Vader with their master-servant thing going on and Palpatine getting off whenever he senses rage in somebody is getting awful close to 50 Shades of Grey territory!

 

Search your feelings, you know it to be true.