Lvl 18 is most fun for sure and the best lvl a mage twink can show its skills is in here but you have to choose the right guild of course...

There are few guilds at lvl 17-19 but this bracet concists of 2 sides

1 side is rebirth.black soul.psycho

2 side is public .mvpvp. and some smaller guilds wich i forgot name of

So i would recomend you to join rebirth its the greatest among all guilds and their player is really good as pvp mates and as frind in game who would gladly help you

Since black soul and psycho is 16-17 guilds would rebirth 17-20 fit you perfect