Life Drain

Type	Weapon
Damage	35 (Magic)
Knockback	2.5 (Very weak)
Mana	10
Critical chance	4%
Use time	12 (Very fast)
Velocity	10
Tooltip	Drains life from enemies
Rarity
Sell	8
Research	1 required
Buff	Life Drain
Buff tooltip	Increased life regeneration
Duration	Until all enemies are killed or usage of Life Drain ceases

Desktop/Console/Mobile-Only Content: This information applies only to the Desktop, Console, and Mobile versions of Terraria.

Draining life from Werewolves.

The Life Drain is a Hardmode magic weapon that has a 20*1/5 (20%) chance to be dropped by Crimson Mimics. When used, it deals constant damage to all enemies near the cursor's position, as long as the distance between the player and the cursor is unobstructed. A stream of red particles flows toward the user from each targeted enemy. While the weapon is in use, the user receives the Life Drain buff, which adds 2.5 life per second to existing health regeneration.

While an enemy is being damaged by the Life Drain, it is also afflicted with a special debuff that deals 5 damage per tick.

Its best modifier is Mythical.

Notes

The Life Drain buff increases the player's health regeneration as long as it is hitting enemies. It does not depend on the red particles.
Its unique debuff can be applied to any enemy that is not immune to all debuffs.

Tips

It is not as effective against single enemies but it is a very effective weapon for crowd control, especially against the Goblin and Pirate invasions.
The Life Drain employs a significantly different mechanic from the Vampire Knives, which actually heal the user based on damage dealt. This weapon instead applies a life regeneration buff while enemies are being damaged which increases in power for every two additional enemies within its effect, but provides slower healing than the Vampire Knives. Both weapons are, however, very thematically similar, being based around stealing health and focused around the Crimson biome. The Life Drain has one core advantage over the Vampire Knives, and that is that the radius of damage that can be dealt is unaffected by single block walls, so keeping a type of box of blocks around the player or standing near a wall/door that has enemies on the other side will assure the enemies die easily if swarmed. The Celestial Magnet and its upgrades and the Treasure Magnet help this even further as they increase the radius in which stars can be picked up, allowing continuous usage of the Life Drain as long as enemies drop stars or near a star statue on a timer.
This is a useful weapon against worm-type enemies since it counts each segment as an individual target. This does indeed work against The Destroyer, though due to the boss and its probes being immune to all debuffs, Life Drain will not increase the player's life regeneration.
It is also extremely useful when fighting the Dungeon Guardian, as the debuff will ignore its high defense.
It does affect Target Dummies as if they were normal enemies, allowing players to heal more quickly after respawning without needing to pay the Nurse.
While the player must aim at an area within their line of sight, the Life Drain can still damage enemies through walls as long as they are still in the area.
Since it is not a direct healing effect, Moon Lord's Moon Bite debuff will not interfere with it in any way.
As it will always take a set amount of mana, but has no max amount of enemies it can damage at once, it is highly effective when attacking huge hordes of enemies.

Trivia

The Life Drain may be a reference to the Life Leech weapon from the 1997 first-person shooter video game Blood, as it bears a similar appearance and also works by draining life in a similar fashion.
The icon of the Hearty Meal buff is the same as that of Life Drain.