Also, forgot to mention: your weapon fuses with your arms, becoming 'seamlessly a part of you'. So you acquire regeneration, fuse your favorite sword with your arm and chop it off. You grow a new fused arm, since the sword is a part of you. Rinse and repeat to grow your own arsenal. When Graft weapon expires, the weapons become accessible (you'll have to clean the arm-goo off of them though).