[question]skill & class

my first question is: what is the best class for PvP in C5 high rate private servers?

and my secund question is: there are some skills in spellsinger that called Elemental Symphony, Aura Symphony and Blizzard i need some seeds or forces to use them right. i have skill wich called Seed of Water and even if i use it i cant use any of the symphony skills, why it is?
and about the Elemental Symphony, this skill need not just seed of water he also need another seeds... where or how to get?
very big thx to helpers:azzangel: