Esuna

Esuna is a recurring White Magic spell in the Final Fantasy games. Its first appearance is in Final Fantasy II. Esuna can be used to cure most types of negative status effects just like its item equivalent, Remedy.

Final Fantasy II
In Final Fantasy II, a party member can learn Esuna from an Esuna Tome. The At level 1, Esuna can only cure Poison and Darkness, but as the spell levels up, it can cure more types of status effects. At level 2, it can also cure Curse; at level 3, it can also curse Amnesia; at level 4, it can also cure Toad; and lastly, at level 5, it can also cure Stone. During a battle, if a party member uses an Esuna Tome, they cast a level 8 Esuna, which has the additional effect of curing KO.

Final Fantasy Mystic Quest
In Final Fantasy Mystic Quest, the Heal spell is found at Falls Basin. It functions identically to Heal Potions, as it can cure any status effect.