Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
plus, walls xerneus easily, takes t bolt easily 2 (watch out for psyshock tho but aegi still remains as the superior xerneus wall) just wanted to say this for no reason :)
I've heard of how good it is, but on my team it doesn't fit since I have no room for a defogger. Stealth rock obliterates it completely, plus some Xerneas carry Psyshock anyway. You're welcome to try it, though