So is + 12 Crimson Mace [2] way better than +12 Erde EA10 [2] and + 12 Robot's Arm [2]?
Base weapon ATK = 80
ATK increased by (Refine*Refine), up to +15 refine.
Level 70 or higher: Per 10 BaseLevel, ATK +5.
Assuming weapon level of 12, then 12 x 12 = + 144 ATK
Assuming character level of 175, then 10 x 5 = + 50 ATK
Total weapon ATK = 274