Perfect World Gold is very useful in the game. One of the better archer skills that deals very good physical damage and has a 90% chance to paralyze the target for a good length of time. However, the 1 fury point requirement makes it average for PvE, as it cannot be used every battle. If you find yourself with extra sp, Colligation Bolt is a great skill to invest in, as it is especially useful in PvP. Leveling Route: You can keep it at level 1 if you prefer, but otherwise level it up with any extra sp. Strategies/Tips: I would use it sparingly in PvE. Do not be stupid and use frost arrow immediately after colligation. In PvP, it typically is used against runners. Just make sure you move in slightly so that when they run, and your colligation is casting, they don't move out of range and cancel out your move! The special effect helps out other lightning skills so that they do even more damage. The longer cast time however makes it not too perfect for PvP since BM/BAR could run you down, but if time allows, it helps out lightning strike nicely. Besides PvP, thunder shock is not really worth using unless fighting against defense enhanced monsters.
