To beat your ranger/Mirror self at lvl 18-20 is very easy, this isn't one of those ultra thought out lvl3 type builds, in fact, it isnt even a build.
If you run up to your mirror, youll notice he switches to a Melee weapon.
Just equip all bow skills and Troll Unguent/Healing Spring (and bring Distracting shot also).
Run up to him and hell switch to an axe, and cant use any skills cept unguent. When he tries to heal pull a Zealot on him(Interrupt his heal...)And boom, he'll be dead if you use Unguent or any of your bow attacks he can't use.
