BTW, this is amusing: the Illusion powers from Dragon 364 were reprinted in Arcane Power, but they screwed a bunch of them up! The errata for Arcane Power is almost all for the illusions, and it just reverts them to the versions in Dragon.
So, with the errata applies, here are the changes Arcane Power makes to the illusion powers we've already approved. I've bolded all the nerfs that I consider significant, as opposed to clarifications:
Grasping Shadows: now has the "Zone" keyword
Phantasmal Terrain: now has the "Implement" keyword; increased movement cost for difficult terrain applies to everyone, not just enemies
Spectral Hound: no longer has the "Implement" keyword; must start in an unoccupied square; gives a +1 power bonus to "all defenses" instead of "AC and all defenses" (I think that's the same thing, right?); sustain is reworded to be much clearer
Enemies Abound: "you and your allies treat the target as an ally for the purposes of flanking" instead of "you and your allies can treat the target as an ally..." (I don't think there's any situation where you would choose not to treat someone as an ally for flanking, is there?)
Illusory Wall: can make an attack only when moves adjacent to the wall, not when it starts its turn adjacent; the attack result only effects the enemy for its current turn (used to be "save ends")
I don't much like the new wording of Illusory Wall. Suppose there's a wall between square A and square B, and I plan the following actions:
Turn 1: move to square A, attempt to move to square B (assume I fail)
Turn 2...N: attempt to move to square B again (keep trying until I succeed)
Turn N+1: go do things on another part of the battlefield
Turn N+2: move to square B, attempt to move to square A
In the old version:
Turn 1: The caster gets an attack as I move adjacent to the wall. If it succeeds, I can't cross the wall until I make a saving throw. Assume it succeeds, so I can't move to B yet. I get a save at the end of my turn.
Turn 2...N: The caster gets another attack as I start my turn adjacent to the wall. SIX cases:
(1) I passed my save last turn, caster chose not to attack: I can cross the wall but I am still affected
(2) I passed my save last turn, caster attacked and hit: I need to keep saving
(3) I passed my save last turn, caster attacked and missed: I can cross the wall and am no longer affected
(4) I failed my save last turn, caster chose not to attack: I need to keep saving
(5) I failed my save last turn, caster attacked and hit: I need to keep saving (I believe multiple successful attacks don't stack here)
(6) I failed my save last turn, caster attacked and missed: I can cross the wall and am no longer affected
Turn N+2: Return to square B: if I crossed the wall due to case (1), the caster gets a new attack as on turn 1. If I crossed the wall due to case (3) or (6), I can cross immediately
In the new version:
Turn 1: The caster gets an attack as I move adjacent to the wall. If it succeeds, I can't cross the wall this turn. Assume it succeeds, so I can't cross to B yet.
Turn 2...N: The caster does not get an attack, since I didn't move adjacent this turn. Since I wasn't attacked, I can automatically cross to B immediately.
Turn N+2: Return to square B; the caster gets a new attack as on turn 1 since he hasn't missed with an attack yet.
That's way less complicated, but also MUCH weaker - it only delays me by 1 turn at most! And also makes no sense - I can push through the wall without breaking the illusion completely?
I suggest accepting the Arcane Power version, but "Whenever an enemy moves adjacent to the wall" to "Whenever an enemy moves adjacent to or starts its turn adjacent to the wall". That way I'd have no obvious way to move through the wall until the caster fails an attack, which makes me immune to it until the end of the encounter. (Although I could get through the wall by having an ally slide me on his turn, or something similar.)