Greatsword of Lost Souls  

 

Because this becomes a 30/40 when the magic isn't resisted, and you get a damage bonus from 2h weapons based on your level.

Any question like that is really pointless tho, it all boils down to "Why would you use the weapon your trainer gives you when you can use your epic?"

Not everybody has the same amount of money, time, or energy for getting certain items as others, that's why every 2hs class was given a chance to use it.