The poke you received is probably produced by a cheat device. There are some that trick the game into thinking that the rare poke is still sitting there waiting to be caught, so the player catches it over and over, but the stats and all are legit. There are some that enable the player to alter any stat, even making the poke have stats or moves that are impossible. If you are going to play against anyone you might feel it is unethical to play with that kind.
I'm not an expert, but I've been learning about it, so if I am incorrect about this info please let me know.
I also enjoy a 100 level poke less because I'm not able to level him up any more, which for me is part of the fun. But that's just a personal preference. But DR is correct, Ho-Oh is considered a very powerful poke and is often used in Uber battles. I doubt the lake pokes will ever get much play.