Osmose (ability)

Osmose, sometimes translated as Psych, Asper/Aspir or Syphon, is a recurring spell from the series. It is normally associated with Black Magic. The spell absorbs MP from one opponent as long as they have MP to begin with. Many bosses and magic-using enemies will cast Osmose (or something similar) on a player character if they are getting low on MP. It works in reverse or not at all against Undead.

Final Fantasy II
Osmose is learned from the Osmose Tome, which is dropped by a few enemies, and is a good way to gain MP quickly.

Final Fantasy IV
Rydia, Palom, Tellah, and Fusoya can cast Psych. It costs 0 MP. In this game Psych had the tendancy to only absorb 1 MP from most enemies, probably due to the fact that they have just that much MP. A few enemies like Red Dragon are a little more prone to Psych, allowing the caster to gain 100-150 MP.

Final Fantasy V
Osmose is a Level 6 Black Magic and Spellblade spell.

Final Fantasy VI
Osmose is learnable from Zoneseek and Shiva. This spell is one of the most potent forms of the Osmose in all of the Final Fantasy series. Osmose absorbs enough MP from your target to replenish your own MP to full, provided the target has enough MP.

Final Fantasy VII
Some enemies use it under the name Aspil. Although not available as a spell, characters can use through the item Ghost Hand. The MP Absorb Support Materia serves as a replacement for the Osmose spell. The Magic Hammer enemy skill also will leech up to 97 MP from an enemy (providing it absorbs 100 MP, but costs 3 MP to cast).

Crisis Core -Final Fantasy VII-
Osmose and Osmoga are two Materia available to Zack, they each absorb different amounts of MP.

Final Fantasy IX
Vivi can cast Osmose.

Final Fantasy X
Osmose is a Black Magic spell found in Wakka's section of the Sphere Grid.

Final Fantasy X-2
MP Absorb is an ability learned by the Black Mage dressphere.

Osmose is a spell that is part of the Arcana skillset used by the Dark Knight. However, it is not learned via the dressphere but becomes available by equipping a relevant Garment Grid or Accessory.

Final Fantasy XI
Aspir can be cast on any enemy target for 10MP and functions on the Dark Magic ability. The only way to obtain a scroll of aspir, from which the spell can be learned, is to do a quest for it.

Final Fantasy XII
Syphon is an Arcane Magick spell that drains MP. In the Japanese version it is known as Aspir. The License for Syphon is Arcane Magick 4 that costs 50 LP. The spell costs 4,000 gil and 2 MP.

In the International Zodiac Job System version, Syphon is listed as Green Magick, its License being Green Magick 3 along with Bubble. It can be used by all four mage job class: White Mage, Black Mage, Time Mage and Red Mage.

Final Fantasy Tactics
Spell Invigoration is used by Mystics, while Beowulf Cadmus can cast Syphon.