Ether (エーテル [ether] in Japanese) is a standard MP heal item in Final Fantasies.
See also Dry Ether.
Final Fantasy I
Buy: 150 gil (sell: ? gil)
Shop: Pravoka, Gaia, Onrac
Drop: Air Elemental, Unicorn
Description: Restores 50 MP
Final Fantasy II
Buy: 2,500 gil (sell: 500 gil)
Description: Restores a small amount of MP
Final Fantasy IV
Use: restores 50 MP
Buy: 10,000 gil (Sell: 1 gil)
Final Fantasy V
Use: Restores 40 MP
Buy: 1,500 gil (Sell: 750 gil)
Drop: some enemies
Obtain: some chests
Final Fantasy VI
Use: restores 50 MP
Buy: ? gil (sell: ? gil)
Final Fantasy VII

Use: restores 100 MP
Buy: 1,500 gil (sell: ? gil)
Shop: Bone Village, Cosmo Canyon, Fort Condor, Gold Saucer, Mideel, Rocket Town, Temple of the Ancients, Wutai
Treasure: Beginners' Hall (Sector 7), Aerith's House, etc
Steal: various
Final Fantasy IX

Buy: - (sell: ? gil)
Synthesize: Echo Screen, Vaccine, 500 gil (Memoria Hades' synthesis shop)
Drop: (various monsters)
Steal: (various monsters)
Treasure: (various treasures)
Obtain: exchange for 450 Chocobo Hot&Cold points at a Chocobo Forest, from Ladybird, from people saved at Cleyra in the cathedral, buy in a package of goodies from Stiltzkin in Burmecia on disc 1 and Cleyra, Fossil Roo and Conde Petie Mountain Path on disc 2, capture 5 frogs at Qu's Marsh (combined total for the marshes), dig up 4 on the world map with the Chocograph 'Streamside', 3 with 'Bird's-Eye Lagoon', 4 with 'Abandoned Lagoon', 5 with 'Forgotten Lagoon', 7 with 'Forbidden Forest' and 5 with 'Forgotten Plains', use Dead Pepper for 9 on ocean bubbles between Lost and Outer continents, impress 0-49 nobles in sword fight during I Want to Be Your Canary
Description: Restores 150 MP. The effect decreases if used in the field
Other: restores 100 MP in the field
Final Fantasy X
Buy: ? gil (sell: ? gil)
Obtain: (multiple ways)
Equip effect: x1 for MP+5%, Aeon effect: -
Description: Recovers 100 MP of one character
Other: deals 100 MP damage to undead target
Final Fantasy XII
Use: restores 50 MP for target
Buy: 222 gil (sell: 111 gil)
Other: affected by Ether Lore (10%-15%-25%), Pheasant Netsuke, Nihopalaoa
Final Fantasy XIV

Use: MP +40% (max 100 MP)
Buy: - (sell: 100 gil)
Craft: ALC 15 x6 - Water Shard x2, Puk Wing, Marjoram, Shriekshroom, Distilled Water
Type: Ether, Stack: 99
Description: Processed via the alchemical extraction of aetheric essence occurring in elemental crystals, the contents of this vial instantly restore a few MP.
Final Fantasy Tactics
Use: restore 20 MP, horizontal range 4 (Chemist ability Item, 300 JP)
Buy: 200 gil (sell: 100 gil)
Shop: (available after Lionel Castle ch2) everywhere
Description: Medicine that restores MP.
Ring of Fates
Use: recovers 100 SP to any player within the AoE
Buy: 15 gil (sell: 7 gil)
Drop: many, many enemies
Treasure: many, many chests and barrels
Type-0

Buy: 2,000 gil (sell: 200 gil)
Shop: Underling, Multi-player menu
Treasure: missions 1-1, 2-3, 3-1, 3-2, 5-2, 6-1, practice missions 5-D, 7-A
Reward: quest 29
Obtain: buy for 400 SPP from the SP shop, many NPC chats, clear 1-9 SOs, from Emina Hanaharu and Kazusa Futahito events, etc
Description: Restores up to 50% MP for one party member.
Airborne Brigade

Shop: -
Obtain: various ranking rewards
Description: Restores 1 BP
Other: usage limit, up to 3 per day
Category: Item