You take the weapon used in the casting hurl it in a straight line up to 60 feet in a direction you choose. You make a normal melee attack, just as if you attacked with the weapon in melee, against each foe in the weapon's path, but you can choose to substitute your Intelligence or Charisma modifier (as appropriate for your spellcasting class) for your Strength modifier on the weapon's attack rolls and damage rolls. a whirling blade gets only one attack against each target. The weapon deals damage just as if you had swung it in melee, including any bonuses you might have from ability scores or feats.

No matter how many targets your weapon hits or misses, it instantly and unerringly returns to your hand after attempting the last of its attacks.