Assassin Guide

First introduced in Build 104, the Assassin is a medium-range fighter who uses a dagger and leather Armour and poisons groups of enemies, damaging them over time. He was widely thought of as one of the weakest classes and was fairly unpopular until the devs bumped his max attack and wisdom up to 60 (from 50) and his wisdom gain per level to 1-2 (from 0-2) in Build 113. To unlock the Assassin you must reach level 20 with the Rogue and the Wizard.
Whether solo or adventuring with friends, the Assassin has a fun playstyle and an ability that takes practice to master. The Assassin can deal high damage to several groups of enemies, without much effort needed, and can get himself easy soulbound damage. Recommended for those who want a challenge that can still yield rewards.

The Assassin has excellent Wisdom (Mp Regeneration) and high damage output.

 But I highly highly recommended high experience player to use Assassin.

I suggest you to start with Rouge and practice with groups first, and then when you start to get comfortable to your class, then start farming in Godlands and improve dodging skills, it'll be really helpful when you first try out Assassin.