Shadow Weapons

Can someone explain to me how these work? I got the Shadow Weapon version of the mage staff.. a D grade weapon.. and it's outlined in pink in my inventory - what does that mean? When I equip it, I do even less damage with spells when I have sword breaker equipped, even though it has ALOT more M. Atk.

Thanks in advance for the help.

Are you using spiritshots with your sword breaker?

The pink line is indicative of shadow weapons to remind you that it will fade after the duration is up.

Yeah that's what it was... i was using b-sps no grade with the sword breaker and didn't have grade d sps for the shadow weapon! i r smart! :)