Wondering if my Celesteela is legit/legal

I have Pokemon sun, but I really wanted an offensive Celesteela. I traded for weeks, hoping to get an adamant one and just when I thought I would never get one: BAM. Level 100 Adamant Celesteela with 6 perfect IVs. These IVs are not hypertrained, they all say "Best". At first I was super excited about this and I wanted to add it to my team for ranked battles, but now I wonder if I even should because I'm doubting the legitimacy of this pokemon.

Is there any way to know if this Celesteela is legal and won't get me in trouble? The only thing about it that's crazy is the 6 perfect IVs. It has the right ball, normal moves, not shiny, the right catch location, the stats are normal for the IVs and EVs (I EV trained it). I just think the chance of 6 perfect IVs is so insanely small that I can't imagine why anyone would give me one. The one I put up on GTS for this was another celesteela that was neutral which I didn't want. If it's legal then I'd be happy to play with it but if it's not, then I don't want to be banned from battle spot. I'd rather try to obtain a legit one and hypertrain than have my fun spoiled over a non-legit pokemon that I got by trading.

I have heard that pokemon bank can check, so if I can put it on pokemon bank (when it's updated) would that mean that it's legal? If there's another way to check I'd love to know about it.

I guess it's legal, but not legit, so up to you if you want to use it. For peace of mind, you can wait until pokebank comes out, but that won't tell you anything about how legit it is, only if it's legal.