Favilludo

So i have kind of a stupid question here: i often use guilty and hanged together and port the hanged to the enemy side first turn by using his horrifying whispers attack on the guilty with the on your heels trigger. So my question is this: is it possible for me to declare the guilty as non enemy, after having declared the attack and flipped for it, thus not attaching the upgrade, but resolving the trigger? I don't think so but i am confused by how freely i can use the "may" in the guilty as charged ability.

Ok thanks, it seemed weird at the time. What would happen if i were to put it on an enemy montresor. Since he has demise(eternal) i would assume the demise on the upgrade would trigger as well, but he doesn't die, so would that allow to summon multiple guilty?

So i was playing a game of 50 ss with jack, running amongst others 2 guilty. My opponent was running an ashes and dust. In the first round, his ashes killed my guilty, therefore attaching the punish the wicked upgrade to it. So far so good. However, as i then killed his ashes, we noticed, that both demise abilities would go off. However, the demise of the ashes and dust would replace the model with the ashen core, wich would keep the upgrade on it, while the punish the wicked just summons the guilty and doesn't remove the upgrade itself. When i then killed the core in the same activation, it summoned a seccond guilty to the table. Is that really how it works or did we get something wrong? And if it is, is it intentional?