I want to thank all Antergos and mesa drivers developers.
When i first installed Antergos i couldn’t launch steam, after a lot of trial i manage to open it, but i couldn’t play the games.
I was lost trying to install Catallyst AMD drivers but at the end i just gave up, and install a Debian on triboot just to play on Steam.
Yesterday i reinstalled Steam and discovered a new package called Steam Native wich installed a lot of libraries.
Also i read that mesa drivers were updated and suport AMD drivers. (and Antergos offered the update)
To my surprise i was able to launch Dota and Trine 2 (just for examples), and i didn’t need to change the mesa driver for the AMD one.

I wanted to thank you, since usually we post our bugs and problems in the forum, so i want to express my gratitude.
Very nice job guys.