Robe of Power.

I highly recommend everyone use magic weapons up until Meteorite gear. The reason I recommend this is because magic users get a good boost from this robe, and if you happen to find Tim well he drops a hat that gives you even more mana and I think more damage.
Here in the screenshot I have the a not so good robe, but the mana reduction is pretty nice. I would shoot for ruby or higher robe. To craft this robe you need to have a regular robe which takes 20 silk to craft. Once that is done you will need a regular robe and 10 of any gem.