I'm having some problems with the following codes, some minor, some major. If anybody could take a look at them and figure out how to fix them or tell me what I might be doing wrong, I'd appreciate it.
Mesprit:
94000130 FFF30000
B2101D40 00000000
2000103B 00000026
D2000000 00000000
This code causes the rival to vanish from his usual location in the Fight Area, and Crasher Wake appears at the foot of Stark Mountain.
Palkia:
94000130 FFF30000
B2101D40 00000000
20000E5A 00000002
20000F4A 00000000
2000101A 000000C2
D2000000 00000000
This code doesn't seem to work at all. No matter how many times I enter the Spear Pillar, the portal containing Palkia never appears. The Dialga code works fine. I have both orbs in my bag.
Heatran:
94000130 FFF30000
B2101D40 00000000
20000EFC 00000001
2000101A 00000040
2000103B 000000DD
D2000000 00000000
This one is a bit touchy. Sometimes Heatran appears. Sometimes it doesn't. I have to exit and re-enter the room a few times to get him to show up, and unlike most (all?) of the other rebattle codes, I can't save the game, remove the Action Replay, load the game, and battle Heatran. It seems that the AR must be present and the code must be turned on for him to appear.
Cresselia:
94000130 FFF30000
B2101D40 00000000
20001026 0000000A
20001049 00000020
2000108A 000000FE
D2000000 00000000
This code works, but it causes the Lunar Wing key item to drop again. However, the boy in the cabin has already recovered from his nightmare, so you end up permanently stuck with a key item in your pocket that you are supposed to get rid of as part of the story. This does not seem to have any effect on gameplay, but it would be a nice thing to have fixed.
Darkrai:
94000130 FFF30000
B2101D40 00000000
2000102B 00000062
D2000000 00000000
This code seems to be fine. IIRC, when I was first attempting to catch Darkrai, defeating and respawning it normally would cause that inn caretaker to reappear and transport you to Newmoon Island himself. This code opens the inn, but the caretaker isn't there. Instead, you have to take the boat to Newmoon Island. I assume that this is normal behavior, and this would be the same way you'd reach the island if you respawned Darkrai via defeating the Elite Four, but I'm not sure on that.
I did not test any codes for Giratina-O at the Distortion World or for Arceus, but the most-recent codes for all of the other legendaries appear to work fine.