Sorry...
Too busy lately. Work is eating up on me.
Anyway, I don't really know how to edit Wally's battle.
But if you want to use his event, simply add these commands...
special 0xD3
special 0x27
special 0x12D
Those will remove the player's first PKMN and will be replaced with a Zigzagoon.
Then...
special 0x9D
That will trigger the Wally battling a Ralts event.
Then...
special 0x28
That will remove the Zigzagoon and return the player's first PKMN.
Save a back-up though.
I ain't quite sure of those codes.
Too busy lately. Work is eating up on me.
Anyway, I don't really know how to edit Wally's battle.
But if you want to use his event, simply add these commands...
special 0xD3
special 0x27
special 0x12D
Those will remove the player's first PKMN and will be replaced with a Zigzagoon.
Then...
special 0x9D
That will trigger the Wally battling a Ralts event.
Then...
special 0x28
That will remove the Zigzagoon and return the player's first PKMN.
Save a back-up though.
I ain't quite sure of those codes.