I think the Ravager +6 is a really massive weapon.
Carsomyr is great.
Celestial Fury is good, only problem is that it's +3(but at least not with the Weimer's Upgraded Items mod)
But I still think that the most, most massive weapons would be the Axe of the Unyielding and Crom Faeyr -- Dual wielded and with +++ in Dual Fighting and +++++ in Axe and Hammer proficiencies.
That's what I'm gonna do with my lil' pal, Korgan.