OK, many thanks for the fast help. We will indeed define that!

Well, that's my exact question... To know if it's correct to use the Guildmage's ability only once (X Y=A B) or if by using it on different targets builds up a new ability on the stack (X Y B A). Because the result is completely different... On one case the Clone stays, in the other the Clone is removed from the game...

When you say:

"X Y B A B A B A ...  which would resolve X Y B A and result in the mage surviving.  Typically I don't really care about the target is, esp when it comes to Azorius Guildmage activations because there are often many options on how to target.  When in doubt, break it down to the stack with the least number of steps."

the result is the Clone surviving, not the mage, right?

Hi, this is my first post and I have a though question...

Player1 has a Legacy Weapon and an Azorius Guildmage in play.
Player2 has a Clone that cloned the Guildmage.

We are on Player1 turn. In its main phase he activates the Legacy Weapon to remove the Clone.
Player2 activates Clone ability to counter the Weapon ability.
Player1 activates Guildmage ability to counter the Clone ability.
Player2 activates Clone ability to counter the Guildmage ability.

And we go on and on.

What happens here?
Thanks