Unerring Weapon

Transmutation
Level: Artificer * 1, Bloodrager * 1, Inquisitor * 1, Magus * 1, Sorcerer */Wizard * 1, Warlock * 1
Components: V, S
Casting Time: 1 Standard Action
Range: close (25 ft. + 5 ft./2 levels)
Target: one weapon or 20 projectiles, all of which must be together at the time of casting
Duration: 1 round/level
Saving Throw: Will negates (harmless, object)
Spell Resistance: yes (harmless, object)
  This spell causes a weapon to veer closer to vital areas, improving the result of a critical threat. This transmutation grants a +2 bonus on attack rolls to confirm critical hits plus 1 additional bonus point per four Caster Levels (maximum total bonus +7). If the spell is cast on projectiles, the effect ends on a specific projectile whenever that projectile is used to make an attack, regardless of whether the attack hits. For this spell, shuriken are considered projectiles.