Revelation Online explains the leveling and advancement of Special Skills
The skills themselves have large effects that can turn the tide of a battle in your favor, so it only makes sense that they'd also have entirely independent advancement options for players. You can level up several aspects of your special skills including cooldowns, duration, damage, and cost; higher-ranked skills will obviously take more time to improve than lower-ranked skills. The Special Skills are your big guns that allow you to do things your class otherwise would be unable to do, so it's worth understanding just how big the guns can be. You can try them out yourself when the game hits open beta on March 6th.