Need an L2 or higher ruling here

[Agrajagzz9]

Ok so I move to cast  {Karn Liberated} my opponent has an  {Academy Rector} and a  {Executioner's Capsule} in play. In respone to casting he kills the rector and grabs  {Decree of Silence}. Is karn countered?

I would say no because he doesn't have priority until karn has been put onto the stack having met all of the necessary conditions of beig cast. Decree doesn't enter until after and so would not trigger because the period of moving from cast to the stack already occurred.

Need a rules citation for this

[Kaleo42]

Ill get your rules citation in a sec, but the trigger is "whenever a player CASTS a spell" in your example karn was alread CAST and therefore the conditions of the trigger were not met.

RESOLVED

[Keyeto]

Here's a rule to consider:

601.2h Once the steps described in 601.2a–g are completed, the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell's controller had priority before casting it, he or she gets priority.

You had already cast your Karn (steps 601.2a-g describe casting). At that time, any triggers will go off, and then YOU will receive priority. Your opponent is unable to activate abilities until they have priority, which at that point is too late. By the time the enchantment hits the field, Karn will have been cast/waiting to resolve.

[Kaleo42]

Thanks, it's a pain for me to cite rules in day to day life since there isnt an easy copy and past function.

[Kaleo42]

Oh and on a seperate note this was a rules advisor level question. An L2 is needed for things like {phantasmal image} copying {mutavault} while it's activated and then someone plays {blood moon}, or how to handle rule infractions.

[Agrajagzz9]

I was only asking because my opponent said he was told by an l2 that it worked.

[Agrajagzz9]

Oh and on a seperate note this was a rules advisor level question. An L2 is needed for things like {phantasmal image} copying {mutavault} while it's activated and then someone plays {blood moon}, or how to handle rule infractions.

Out of curiosity how does that work?

[Keyeto]

Oh and on a seperate note this was a rules advisor level question. An L2 is needed for things like {phantasmal image} copying {mutavault} while it's activated and then someone plays {blood moon}, or how to handle rule infractions.

Out of curiosity how does that work?

{Phantasmal Image} would copy {Mutavault} and become a non-animated one, as the animation ability is not a copy able characteristic. Then, {Blood Moon} would make it a mountain. You would have a Land - Mountain Illusion named Mutavault in the end.

[Kaleo42]

I was only asking because my opponent said he was told by an l2 that it worked.

Often times people will misunderstand a judges answers and attempt to apply them to non relevant situations. Also sometimes people will become judges and then think they still know enough to be answering judge questions after years of inexperience.

[Kaleo42]

Oh and on a seperate note this was a rules advisor level question. An L2 is needed for things like {phantasmal image} copying {mutavault} while it's activated and then someone plays {blood moon}, or how to handle rule infractions.

Out of curiosity how does that work?

{Phantasmal Image} would copy {Mutavault} and become a non-animated one, as the animation ability is not a copy able characteristic. Then, {Blood Moon} would make it a mountain. You would have a Land - Mountain Illusion named Mutavault in the end.

Good job