Leveling phys?

[Hadesengel]

Hi, relative noob here.

What kind of weapon do I best use to lvl phys (atm: phys 8) and what would it cost to buy one?

EDIT: Thinking about it: Better question would be what kind of weapon should I get at all (and what woud it cost)?
because atm I just have a plain X-Mas flame sword, with no upgrades/blessings at all, and I can (logically) only inflict minimal damage.