Mana Drain

Surveillance Ball footage of suspect. Wanted for Unlawful Tapping Of Mana.

A subtrope of Mana Burn - a power that drains someone else's Mana Meter and gives it to the caster. Useful both to replenish the user's mana and to prevent the enemy from being able to attack back. Some opponents die when they lose all their mana.

When this is done to Hit Points, it is Life Drain.

Compare Liquid Assets.

Examples of Mana Drain include:

Anime

Naruto has encountered several enemies who have the ability to drain chakra. Most notably, Orochimaru's spy, who actively absorbed his enemy's chakra though his palm (he fought and lost to Sasuke in the preliminary of the Chunin exam).
Bleach has Zaraki's eyepatch, which feeds on reiatsu. Also function as a Power Limiter
- Yumichika's zanpakuto could drain his enemy's reiatsu, essentially instant win
A machine in later episodes of Magical Project S is capable of this on a mass scale.
Many characters in Dragonball Z can absorb Ki from attacks. Android 20, a.k.a. Dr. Gero, once suckered Vegeta into using an extremely powerful attack to obliterate his hiding place, only to zip out and slurp it up through his hands before it hit.
- This is played with later in the Buu story arc. Goku fights Yakon, a creature on Babidi's ship that drains his power whenever he turns Super Saiyan. He destroys it by turning Super Saiyan 2 for a very brief moment; the sudden influx of energy is too much for the creatures body and destroys it.
Negi Springfield of Mahou Sensei Negima in his dark mode does this using black flames.
- To be more specific it's he only does this after absorbing a specific spell - "Hell's Conflagration".

Tabletop Games

The color Blue in Magic: The Gathering has a host of such spells, as pictured above. Three such spells are Drain Power, Mana Drain and Mana Short.
- Mana Drain was so overpowered that Mark Rosewater, head of R&D, famously stated that the entire R&D team would have to be hit by a bus before they'd reprint it.
Steal Energy in GURPS is a highly restricted version of this.
Power Leech, a psionic power from Dungeons and Dragons, allows a Psion to slowly drain power points from other psionic characters, although only a fraction of the drained points are added to the attacker's reservoir.

Video Games

The Rasp/Asp/Aspil/Aspire/etc. and/or Osmose in the Final Fantasy games. Magic Hammer occasionally works this way, but usually just lowers the target's MP.
- Final Fantasy VI has several enemies (the most famous being Ultima Weapon/AtmaWeapon) who will die when their MP reaches zero.
  - One way of defeating MagiMaster involves doing a lot of Rasp and Osmose. Slow? Sure, but the "Ultima / Not enough MP!" is very satisfying.
- Magic Hammer pulls triple duty in Final Fantasy XI, what with not only draining MP and giving it to you, but causing HP damage as well. Blue Mages can only learn it at level 74, however. There's also Aspir Samba, which Dancers use to let party members drain an enemy's MP.
- There's also White Draw, a Dragoon skill in Final Fantasy IX. It drains MP from an enemy and splits it among all the current party members.
- Final Fantasy VIII has the draw command, which lets you pull spells out of the enemies' bodies to replenish your own stock. Beware, however; some enemies, such as Ochu and The final boss can mana drain you.
- In Final Fantasy Tactics A2, spells are kept from being overly powerful by MP starting at zero and regenerating 10 each turn. For this reason, Osmose's straight MP drain would be too powerful when used by a mage class, and we instead get the Arcanist class's "Syphon" spell which drains the opponent's MP and restores an equal amount of the casters HP. The Lanista attack "Sword of Light" still does this conventionally, probably because Seeq don't have a lot to spend MP on.
City of Heroes has all sorts of endurance drain powers. On the critter side, the Malta Sapper has the most obvious and drastic (half your total Mana Meter in one hit), though there are others (Arachnos Mu are less powerful than Sappers, but much more common). On the player side, Power Sink, Transference, Short Circuit, Energy Absorption, every Electrical attack, and most of the Kinetic ones.
Mana Drain from Shin Megami Tensei Nocturne.
The Lord of the Rings Online has the Loremaster player class, which can drain power from opponents and pass it to teammates. Certain enemies, such as the undead, can apply disease debuffs which drain your power.
Some of the Dragon Quest games have enemies doing a "strange dance" which lowers one's mana. This was referenced in the baseball episode of Suzumiya Haruhi ("Is Haruhi trying to lower the pitcher's MP?").
- A couple of heroes can perform this dance as well. Taloon from DQIV, for example, does this at random times.
The Blood Mage in Warcraft III: The Frozen Throne has an ability called "Siphon Mana". This can also be used on allies, draining mana from the Blood Mage into the ally.
In World of Warcraft, shadow priests have this ability. They also have Mana Burn, which drains the victim's mana and hurts him by the same amount at the same time.
- Mages can do this to themselves, sort of; Mana Shield will cause them to lose mana instead of health when struck.
  - Lady Deathwhisper, a boss in Icecrown Citadel, starts the fight with a mana shield which gradually drains her mana as you chip away at it. You can't even begin to hurt her until her mana pool is exhausted.
In EverQuest, Necromancers and Enchanters are masters of this trope. Actually, Enchanters are mostly obeying this trope in raids. They rarely use their (otherwise totally inoffensive) damage spells, but they use all their versions of Mana Drain (one of them even named that). Similarly, Necromancers do this, and their inversion: Mana Pump.
"Mana Drain" is one of the many spells in the Warlords Battlecry series. Also, an electrical attack will drain mana as a side effect on a critical hit. Both of these only empty the mana meter of the enemy, it doesn't steal it.
Guild Wars characters have access to a wide variety of mana-draining skills. Ironically, the similar abundance of mana-boosting skills (especially the Necromancer's powerful Soul Reaping ability), coupled with the fact that most of the monsters are oversupplied with mana to begin with, has led to mana-draining skills being widely thought of as underpowered and pretty useless.
Star Wars: Jedi Knight: Jedi Academy has "Force Drain" as a dark power (it was also available in the predecessor Jedi Outcast, in multiplayer only).
- If it's used on you, once you run out of force power, it starts draining your health. Really powerful bosses can kill with it.
  - Similarly, Star Wars: Knights of the Old Republic 2 also had "Force Drain" as a Force power you could choose, but as you ran into maybe a dozen Force-using enemies in a game it was largly worthless.
Super Robot Wars has the Energy Taker, which does exactly what the name implies.
The Snow Clan of the Disgaea series does this as their class ability. Fubuki does this directly while Yukimaru has the Hyuuga clan variant (physical attacks have a chance to inflict amnesia which disables use of special attacks).
In the MMORPG Anarchy Online the trader profession has powerful abilities that drain other players nanoenergy (mana in the scifi game)in pvp combat, leaving many professions crippled.
This was one of the ways you filled your Mana Meter in Silhouette Mirage, a PSX platform shooter. Facing one way would make you fire either life- or mana-draining bullets, depending on which kind of opponents they were. Facing the other way reversed them. Very 2-d of the game. Of course, if you didn't want to turn around you could burn 1/3 of the mana meter with a special reversal move.
Tales (series) games have the Weak/Waste status, which caused your TP/CG/EG to either slowly drain or take more than usual to use attacks.
The game itself performs a "Mana Drain" on both you and your opponent in Puzzle Quest: Challenge of the Warlords when there are no more available moves.
Titan Quest features several random weapon properties and a skill or two that damages mana.
The Mother series of games features "PSI Magnet α/Ω". Both moves are free, alpha drains from one target, and omega drains from all enemies. The catch is that the enemy has to actually be able to use PSI in order for PSI Magnet to drain PP. Fobbies are great for this, because they attack in large numbers, but start with a status effect that prevents their PSI from working. Just don't overdo it, because it'll really hurt when that status effect wears off.
Present as a Mage spell in Nox, and notable for how it can drain mana over time both out of living beings as well as mana crystals and pylons.
The Shin Megami Tensei series has Mana/Spirit Drain, depending on the game. Very useful in the SMT line, not so much in the Persona line (where you're lucky to get better than twenty points back).
- Of course, while it's something of a Useless Useful Spell for the player in the Persona series, enemies using said ability are even further into Demonic Spiders territory than quite a few enemies already are due to the difficulty of replenishing SP, particularly in Persona 4.
- A more useful variant is in Devil Survivor, that may even be considered a Game Breaker; it gets both H P and MP, is unblockable, and is nearly the only way to restore MP mid-battle.
The Absorb Magicka spell from The Elder Scrolls series works like this, though it's usually useless, considering that it generally replenishes the magicka that you just used casting it. But if you forwent Destruction in favor of Mysticism/Restoration, then you don't have access to Drain/Damage Magicka.
Defense of the Ancients Lion has a channeling mana drain. His counterpart from Heroes of Newerth, Witch Slayer, shares the same ability.
EVE Online has energy vampires (usually called nos, or nosferatu after some of the different types available) that transfer some of the target ship's capacitor energy to your own. Something of a game breaker before being patched to not drain the target's capacitor to a lower percentage than your own. Some ships have bonuses to the drain amount of nos and neuts, the related mana burners.
Maple Story has a passive version of this, called MP Eater, for wizards of all classes that has a percentage chance to drain a percentage of a target's mana for every magic attack. Because of the way it triggers, it's useless for actually gaining mana and mostly serves to lighten the cost of mana potions.
Dark Heart of Uukrul had the Sator and Rotas spells for this purpose. (One created a link, the other drew mana through it.)
Kinnikuman: Muscle Fight
- Beauty Rhodes can drain super meter with his pinfall.
- Buffaloman can drain super meter with his horn. If Buffaloman has a full super meter, he takes damage.

Western Animation

An episode of Aladdin had the Crystal of Ix, which allowed Evil Sorcerer Mozenrath to steal the Genie's powers.