they are the "ultimate weapons" and their bad stats can be removed. As for a scythe Quake scythe but it is earth elemental so it wont work against some enemies including gabriel celeste and ethereal queen.
I'm pretty sure you cannot remove them. As for the negative stats, you can usually find something that counters it, Example, Conqueror Scythe "Asura Vajra has a -1999 Defense Penalty, It goes for 1.2m Fol. As for the Battle Armor, It adds 4999 Defense, and you can net that for 800k Fol.
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