Rules Questions

[apegamer]

"...when this card enters play" was really confusing, since it never seemed to come up. Does the ambush happen the first time that creature is fought (as the card comes to the top of the stack) or only if that card is played as the top card?

If the monster is encountered on the turn it comes into play.

I also found it a bit perplexing that Xykon is always on the top of his own stack, and that the dungeon collapse ends when he is defeated. From the comic, I'd have fought you have to fight a roomfull of people to get to him.

Monsters below Xykon are used to beef him up. The 'big fight' before meeting Xykon happens in the other rooms in Xykon's Lair.