Additional skills

What additional skills should I go for with each class? Also is there a wiki for this game?
Go for the ones that are max damage. Doing most damage for multiple enemies isn't the best after getting over lvl200. One massive relate makes you effective vs miss raids and pet yard
1. Class oriented additional skill
2. Sharp attack
3. Final attack

This is the most efficient order.

However, I see some korean players go stat transfer 2nd and sharp attack 3rd with zeus sword - harvest / gold rich armor / cursed accessories with horror 98% and maximize the stat boost. This setting is mostly for challenge top usage Hydra.