- "From the world view, the Espers of Revenant Wings are born of a different power than those of Final Fantasy XII."
- —Motomu Toriyama
- See also: Summoned Monsters.
The Espers, called by the aegyl as the Yarhi, in Final Fantasy XII: Revenant Wings are distinct from those of the other summons in Ivalice games. Unlike the Scions or the Espers of Final Fantasy Tactics, these Espers are unique to Lemurés in origin, and have their distinct history.
For unknown reasons they still resemble the standard Espers of Ivalice. This similarity to Ivalice summon magick leads to them being called Espers by outsiders. There are a total of 51 Espers in Final Fantasy XII: Revenant Wings.
The Espers of Lemurés are, unlike those of Ivalice, born from the stolen anima of the aegyl through the use of auracite. These stolen aegyl souls gathered, creating their own plane, the World of Illusion, and it is from here they can be called to the material world via a Summoning Gate by a person carrying auracite. In doing so the summoner's anima is eroded, creating more Espers.
The Espers from Final Fantasy XII are also present in Revenant Wings. They were attracted to Lemurés due to all the activity going on.
Vaan and his sky pirating friends at first try to protect the auracites from harm, but come to learn of them sapping the aegyl of their anima. After all the auraliths are destroyed Vaan and his friends are transported to the World of Illusions where they learn more about the nature of anima and the Espers. The group fights against the aegyl god Feolthanos who has purposefully been draining the aegyl of their anima and who wants to attack Ivalice. After Feolthanos and the auraliths are all gone, the aegyls' anima is released and the Espers and their world fade from existence.
Espers are bought on the Ring of Pacts. There are four main elements, plus two additional areas for summons. Each element, bar Holy, has melee, ranged and flying summons. Each of these areas has three ranks, with rank 1 being the weakest and rank 3 being the strongest.
The player does not need the rank 1 summon to get the rank 2 summon, and neither are the rank 2 summons required to get the rank 3 summons. Melee summons are strong against ranged, ranged are strong against flying, and flying are strong against melee. Some summons, mainly the Espers from Final Fantasy XII, must be defeated in battle before becoming available on the Ring of Pacts. The Espers of Final Fantasy XII: Revenant Wings act as party members in battle, and multiple instances of each can exist on the battlefield at any given time, bar rank 3 summons, that always appear alone.
Non-elemental summons have no weakness or resistance and tend to have no special attacks. They are best used for fighting a group of enemies with different weaknesses. The game's most powerful summons are non-elemental.
Fire summons are weak against water summons. They are strong against earth summons, and some water (ice) summons.
Water summons are mainly weak against thunder summons, while Shivan, Shivar, and Shiva are weak against fire. They are strong against fire summons, and some thunder summons.
Thunder summons are mainly weak against earth summons, while Ramih and Remora are weak against water. They are strong against water summons.
Earth summons are weak against fire summons. They are strong against thunder summons.
Holy summons have no offensive capabilities. Instead, they can only heal your party members with their attacks. The sole exception is Ultima's special attack, Eschaton.
The word yari is Japanese for "spear", which is the typical weapon of the aegyl. This alludes the Yarhi being the blade of the aegyl.