I ran across someone in Seekers who needed help beating his doppleganger
with his Mo/W. If everyone already knows this pls dont flame me too hard.
OK its super easy. Take only two skills.
Deadly Riposte - Bought in fishermans haven. (just North of Sanctum Cay)
Riposte - cap from a boss in Divinity Coast or buy it in copperhammer mines.
Dont take any other skills, leave them empty.
Need any sword. Max tactics and rest in swordsmanship.
Use deadly riposte before you step on the last stone then skip cut and
run straight up to the dopple and attack.
Then start spamming riposte.
15 sec or so later he is dead.
My personal best time was about 10 sec. while i was naked.

You will take some damage with low armor, but ohh well.
I used to use for great justice for the adrenaline gain, but its not needed.
Anyway, for any newbie Mo/W needing ascended, i hope this helps.
Later,
Strom