FF6 summons question

Starlet: Jidoor mansion in WOR.
Kirin: Zozo, when you find Terra in WOB
Phoenix: Star-shaped mountain range in WOR
Unicorn: Magitek reaserch facility, WOB
Palidor: Solitary island after Celes leaves, WOR
Sraphim: Bought from theif in Tzen. 3000 GP WOB, 10 GO WOR
Ifrit: Magitek reaserch facility, WOB
Shiva: Magitek reaserch facility, WOB
Odin: Ancient Castle (Underground between S. Figaro and Kohligen) WOR
Manduin: Magitek reaserch facility, WOB
Raiden: Changed fron Odin, Ancient Castle basement WOR
Bismark: Magitek reaserch facility, WOB
Crusader: Defeat all 8 dragons, WOR
Ramuh: Zozo, when you find Terra, WOB
Bahmut: Defeat Doom Gaze, WOR
Shoat: Magitek reaserch facility, WOB
Tritoch: Hills of Narshe, WOR
Alexandr: Doma castle throne room, after Cyan’s soul sequence
Zone Seek: Auction house in Jidoor, 10,000 GP
Ragnarok: Weapon shop in Narshe, WOR
Golem: Auction house in Jidoor, 20,000 GP
Terrato: Umaro’s cave in Narshe, WOR
Stray: Zozo, when you find Terra, WOB
Carbunkl: Magitek reaserch facility, WOB
Fenrir: Defeat Phunbaba, WOR
Phantom: Magitek reaserch facility, WOB
Siren: Zozo, when you find Terra, WOB

To summon them, you move the controler in the magic screen up past the magis spells. An esper can only be summoned once per battle.