That weapon does not seem to be particularly good, or is it just me? I don't care about the gfx either. I think I'll stick with getting my rank up.
Not as good as Grief Sword, but it has total 35 upgrades. The game has a lot of Blade users, so it was worth it for me. I used the following strategy to get it without Revives (YMMV):
Get High Lvl Barienna either own or a friend to bring in Mana and for the Shield Skill.
Go in with High Level Knights. The Mission has TONS of archers/Archer bosses.
Juliana in reserve boosting Attack for your party.
Bring 1-Mana Healer along as the bosses hit hard. The higher level, the better.
Bring as many Frost Weapons as you can. 2 Minimum.
Do not bring any Fire weapons/Wizards.
Whenever you are low on health, use Barienna, then heal. Barienna+Healer means that in most situations you can stem the damage at least a bit.
3rd Stage final wave is 3 Archer bosses, engage them ASAP.
At least 1 Mass Damage Skill is nice, especially if it is Frost Damage or Skill with a Status effect.