Summons

Eidolons, or summons, are powerful creatures that can be called by Dagger and Eiko to aid your party. This guide lists all the Eidolons, their attacks, how to get them, and other useful tidbits. I have done my best to ensure that this guide is accurate and complete. If you notice a mistake, please let me know.

Summoning Secrets

Changing Eiko's Summons
Eiko's summons, Fenrir and Carbuncle, have different effects depending on what Add-On she has equipped when she summons them. The effects are listed below.

Dagger's Summons
Two of Dagger's summons, Atomos and Odin, work according to a given formula. Atomos drains an enemy's HP by a given percentage, determined by the following formula:
The number of Amethysts in your inventory + 30
The above formula works when the full animation of the summon is shown. If the short animation is shown, the damage is equal to 2/3 of the above formula.

When Dagger summons Odin, he attempts to immediately KO the enemy. The chances of his attack succeeding is determined by the following formula:
Dagger's Magic Power divided by 4, plus Dagger's Level minus the monster's level.
In other words, the higher Dagger's Magic power and level, the better the chances of success are. If Dagger equips the Odin's Sword support ability (learned from the Ancient Aroma item, 50 AP) Odin will attack physically if his KO attack misses.

Strength of Summons
Summon animations can be either full (the eidolon itself appears during the animation) or short. If the full animation is shown, the eidolon's attack will be more powerful. The Eidolon always appears the first time you summon it, and will randomly appear thereafter. Eidolons are more likely to appear when Dagger uses her Trance attack Eidolon, or when she or Eiko equips the Support Ability Boost (learned from the Pumice Piece, 150 AP for Eiko and 190 AP for Dagger).

The strength of a summon is also affected by how many of a particular jewel you have in your inventory. Check the chart above to find out which jewel is associated with which summon. You can win most of the jewels from various enemies, except for Pumice, Dark Matter, Phoenix Pinion, and Aquamarine. You don't need extra Pumices or Dark Matters. Phoenix Pinions can be stolen from just about any enemy after Disc 2. You can get extra Aquamarines by putting Ores into the statue of the Sea God at Daguerreo - 5 Ores = 1 Aquamarine. In addition, you can synth most of the jewels from Ores and other items on Disc 4. See the chart below. (Note that the chart does not list Lapis Lazuli, although it can be synthed, because it does not affect any Eidolons.)