Enhancing using T2 blue stone

[Hessah]

Blue Miles prevents your weapon from degrading..

if your weapon doesnt not have a grade (at +0) you cant really degrade from 0... so it wont let you use it...

as soon as ur bow hits +1, you'll be able to use ur blue miles

(but keep using ur red perfect at +0, coz your weapon could still break at +0)