GS u get in Korea.
u need to talk to the statue in waterfall near Holy Village first
and u need 5 stars for get the skill.
for burst u need at least 2 fires.
u can burst with water + earth + 2 fires
well u can try with 1 fire too.. but u'll get less then 1k exp xD
Lv: 13x Water Knight [Andrams], 12x Fire Kiler [Pyro], And Many More :3
Server: Virgo