>>29977496Almost all the posts on solving it are made by me, but I'd be very surprised if the Latios trick didn't work for you. This is the original one I used from the anon's save file, although if you have a look at the save you will realise that I forgot to match the trainer name to Latios' original trainer so it was quite disobedient.
Another anon has this opinion on it if you feel like testing stuff
>>29923253 