can use any skill character and items do not matter do whichever you take a liking to

Essences are used in transmutting items by putting in same quality(tier 1 w/ tier 1) magical + item with the corresponding essence to reroll stats on an item. They are also used gor sufgusing fish which adds enhanced effect which enhances the healing power or mana for the fish. I think the fish must be cooked first but in not positive

This post was edited by SmokeyMcPot1990 on Jul 9 2012 09:50am

which skill i should use on dagger rouge?

I am guessing that you mean Abilities and not Skill... they differ.

Use the ability that you are comfortable...

if taking hits constantly (dmg) then maybe Retribution or TwoHitBack (note 2hitback = if you have passed to samurai)
another main one for solo'ing (and in some cases in a group) = Salvation.

Later on you will get comfortable with the abilities.