Ultimately the choice is yours but if you would like my opinion I believe that your powers are in two totally different categories. Nyx's is like you said, Illusions. While what he does is exceptionally astounding, they are nothing more than mental images that shock his opponents into a state of fear. To a lesser degree he could attack people's pain inducers.
While you are directly controlling your opponents. Now, I will ask for you to limit this as this could upset several PC players if you attempt to control with malicious intent or without permission. I like the idea as yours is a more direct and absolute method of doing creating chaos in the enemies ranks. But I want you to know that it won't be nearly as effective on the Dominion Three as it would be demons, because they have nothing to fear and immensely strong wills.
Is it possible to create a Pokemon gives script that is also a yes/no?
Yep, it's possible.
Here's an example.
if 0x1 goto @done
message @1 5
compare lastresult 0x1 //checks if player chose 'yes'
if 0x1 goto @yes //goto @yes if player did chose 'yes'
if 0x0 goto @no //goto @no if player didn't chose 'yes'