If I cast {Angel of Serenity} and my opponent respondes with {Restoration Angel} to blink a creature he controls, am I now allowed to exile {Restoration Angel} and/or still exile the blinked creature?
Even though you get to choose whether or not to exile the creature upon the Serenity's resolution, you have to choose targets upon ETB. You can't then change targets. His Restoration Angel will go on top of the stack, and his creature will be safe from your Serenity. As far as I know, it goes like this:
1.) Serenity ETB. The effect goes on the stack. You must choose your targets here.
2.) Opponent Resto Angel's. Targeting his creature. The flicker ability goes on the stack
3.) Resto Angel's ability resolves. Exiling his creature.
4.) Opponent creature comes back.
5.) Serenity's ability resolves. You then get to choose (since it's a "May" ability) to have it actually resolve or not. But you can't choose new targets.
I think this is one of those instances where the difference between your angels resolution and the ETB triggers resolving come into play. If he flickers his creatures while your angel is on the stack then nothing happens bc you haven't chosen anything yet. However if he waits until the spell resolves, you choose and those choices go on the stack, then flickers then his creatures are safe. Not 100% sure so can someone either agree or tell me I'm an idiot lmao
The two of you are correct
Both are almost 100% right. Ill clearify.
Serenity is cast
Priority passes
Serenity resolves and enters te battlefield adding her ETB to the stack
Targets are chosen (this is the may part, you dont have to choose anything or all three if you dont want)
Priority passes
Resto is cast
Resto enters putting her abilit on the stack
Target is chosen
Priority passes back
Resto resolves flicking the target making it a new object
Serenity resolves exiling all targets that were origionally chosen and have not changed zones since the target (this means the resto target is saved)