True, I haven't won pokémon "leauge",
I have only won pokémon league in Red, Blue, Yellow, Gold, Crystal, Ruby, Sapphire, Emerald, Diamond, Platinum, and soon HeartGold.
So you were right as you didn't write league right.
I was too slow!!!
So, I answer to you too.
I have done that one time in Ruby and one time in Mystery Dungeon.
So you were wrong too.
TPBMHN bought Slowpoketail.
(You can do it in game without cheating)