Frost Weapon (enhancement)

Source

3-core enhancement

simple or martial melee weapon

This weapon faintly glows with a pale-blue color, and while charged white runes light its surface. The air around it is always cool, and while the weapon is on one's person one can tolerate extreme heat without difficulty.
     This weapon has 4 charges. Every attack with it expends one of the remaining charges, regardless of whether or not the attack hits or misses. When the wielder hits a creature with this weapon while expending a charge, add a d4 bonus die to the damage roll as cold damage.
     A creature which takes any of this cold damage unreduced must make a DC 13 Constitution saving throw at the end of the current turn. On a failure, the creature is petrified until the end of the wielder's next turn or until the creature takes damage, whichever comes first.
     After no attack has been made with this weapon for 1 minute, it fully regains its charges.