- Diabolos is subject to a perpetuation cost based on the level of the Summoner. See Avatar Perpetuation Cost.
- Diabolos's perpetuation cost starts at 1 MP/3s at level 1, becoming 13 MP/3s at level 99, before Refresh or Auto-Refresh effects.
- Resistant to dark-based damage and enfeebling effects, including dark-based Sleep effects.
- Weak against light-based damage and enfeebling effects.
- Avatar's Favor effect: Refresh (Diabolos's Favor).
Diabolos's Blood Pacts are all dark-based.
|Ruinous Omen||1||LVx2||T||Required MP: Caster's level x2. Uses all MP and reduces the HP of enemies within Area of Effect by a random percentage.||The cap on the percentage is reduced against some monsters.
Available only while Astral Flow is active.
|Camisado||1||20||S||Deals physical damage.||Skillchain property: Compression.|
|Nether Blast||65||109||T||Delivers a ranged attack that deals darkness elemental damage.||Ignores shadows & deals direct damage. Damage is only affected by Pet Magic Attack Bonus effects, and is only reduced by target's innate Magic Defense Bonus or Stoneskin.|
|Night Terror||80||177||T||Deals Darkness damage to an enemy.||If the target is asleep, this ability deals ~40% more damage.|
|Somnolence||20||30||T||Weighs target down, and deals magical damage.||This is the only "Blood Pact: Ward" that directly deals damage.|
|Nightmare||29||42||T?||Deals darkness elemental damage that puts all enemies within Area of Effect to sleep and gradually reduces their HP.||The ability inflicts two statuses: a special Sleep effect and a damage-over-time Bio effect.|
|Ultimate Terror||37||27||T?||Decreases attributes of enemies within Area of Effect.|
|Noctoshield||49||92||Gives party members within Area of Effect the effect of "Phalanx." Lasts 180 seconds.||Not as potent as the spell.|
|Dream Shroud||56||121||Enhances magic attack and magic defense of party members within Area of Effect. Lasts 180 seconds.||Grants separate Magic Attack Bonus and Magic Defense Bonus buffs. Amount of Magic Attack and Magic Defense is dependent on the time of day: +10% Magic Attack and very little Magic Defense at midnight, +10% Magic Defense and very little Magic Attack at high noon.|
|Pavor Nocturnus||98||246||Inflict Death on target. If target is not affected by Death then will give the effect of Dispel instead.||Possible to increase success rate if target is asleep. Possibly a greater increase of success if target is under the effects of Nightmare.|
1 S/T column indicates whether a particular Blood Pact participates in Skillchains (S) or uses TP (T). Blood Pacts that use TP can be used as a Magic Burst; however, Astral Flow can also Magic Burst even though it does not actually consume TP.