I'm planning to build a singles team on showdown around him and I was wondering if I would get rekt.
For sure. One of the better Mega Pokemon in OU, in fact. For a number of reasons:
Before you just throw it onto a team, keep in mind some of its flaws that you'll need to cover up with your team.
Totally viable, just watch out for stealth rocks. He can even go mixed with 130/130 offenses, though obviously not fully special. Here's a sample I like though
[email protected] naive nature
-flare blitz/fire blast
-dragon pulse/outrage/dragon claw