Terraria (Wiki): Crystal Vile Shard

The Crystal Vile Shard is a magic weapon that summons 7 to 8 snake-like crystal spikes and a head that extends up to 16 to 18 tiles, pierces through walls, and damages all hostiles caught within. The Crystal Vile Shard’s head deals 125% of the weapon’s damage and knockback. It is a direct upgrade to the Vilethorn.   Like Vilethorn and Nettle Burst, the Crystal Vile Shard will travel for 2s before disappearing. During the duration, enemies without the knockback immunity will be stun-locked, penetrate DEF by 10, and damages enemies 7x   Combat-wise, the Crystal Vile Shard has less range and damage, although it possesses a strong stun-lock potential against enemies. Enemies and bosses with segmented bodies are also more susceptible to the Crystal Vile Shard’s repeated damage, although Ichor is still recommended for more armor penetration.