Every time I start a new HGSS game with a specific spread, I have to beat that game to properly RNG that spread. So you need to ask me if I beat the game with the spread you're interested in, not if I beat HGSS, because I've beaten it on several games already. For the adamant spread, it's ready for RNG, but like I said, I have to trade an Arceus over to my adamant spread game to unlock the event.
Even if I did use a hacked Arceus, it would unlock a legit event. Once the event is unlocked, the poke generated from it will also be legit. In any case, I'm using a legit Arceus that I got from Supe. And no, his poke is not a redis Arceus.