Vampire Knives

The  are a new weapon which was added in the 1.2 update.

They can be found in Crimson Chests, which can be found in the Dungeon. In order to open the chest, you will need a Crimson Key which can be obtained by killing monsters in The Crimson after Hard Mode has been enabled for your world. The drop rate for these keys is 1:4000.

Bonuses
As the weapon does melee damage, the Hallowed Melee Set will apply damage bonuses to it along with any other accessory or Armor Set that boosts melee damage.

A portion (~7%) of the damage dealt will be returned as health to the user. The knives can hit multiple enemies or hit a single large enemy multiple times. You will throw 4-8 vampire knives at a time. For example:


 * One of the Knives hit your enemy and deals 90 damage, but 7% of this damage (i.e., 6) is returned to you as HP. This permits effective invincibility, due to constant healing &mdash; as long as you continue to throw the Knives. They are capable of healing almost all damage inflicted to you fairly quickly.

Due to their healing effect, the Vampire Knives are an extremely effective weapon against Bosses.

Issues
The knives have a huge, and seemingly random spread, making aiming them all very difficult. Despite this, it's fairly easy to survive most encounters and out-heal any damage you may receive. Especially from bosses, where the lifestealing properties of this weapon can be seen in full effect.

However, continued use of the knives can be extremely disorienting with all that's going onscreen. It can be difficult to discern where enemy projectiles or ranged attacks may be, and you could die from not being able to see your avatar among the knife storm and healing beams while they are being damaged.

Trivia

 * This weapon is likely a reference to Dio Brando from JoJo's Bizzare Adventure; a time-stopping vampire who throws knives in an identical fashion. Specifically, this is much like Shadow Dio's knife throw from the arcade fighter of the same name, who's knives fan out in a manner similar to this weapon.