Do you know how stupid that sounds? A Powersave clone, trade glitch clone, and a Pokecheck clone are
ALL the same in this case. If we were talking about a non-event ribbon'd 'mon, then my statement would have been much different.
The only arguable excuse in this case is that either:
1. The Pokecheck Keldeo came from an emulator/backup, since special ribbon 'mons can't be put on the GTS (a.k.a. uploaded to Pokecheck), or
2. The Pokecheck Keldeo was RNG abused on a retail cart and then traded to a backup, then uploaded to Pokecheck.
Either way, unless you pick an obvious hack or from a questionable/unknown uploader, the Keldeo are the same. The Legality Analysis is your friend.
Here, once again I've done the searching for you AND even found a freely available one from a known and reputable user (in fact, the owner of Pokecheck):
https://www.pokecheck.org/?pk=1495468
And here's one from Voodoo:
https://www.pokecheck.org/?pk=1557823
And this one's from loprs:
https://www.pokecheck.org/?pk=1966957
And on and on.