Astral Flow is the Summoner's Two-hour ability in Final Fantasy XI. When used, the player is allowed three minutes to use an Avatar's "Astral Flow Blood Pact". These are very powerful offensive Blood Pacts that can deal a great deal of damage, and affect enemies within an Area of Effect. In addition, the summoner's Perpetuation Cost is reduced to zero, and elemental spirits will have greatly increased casting speed. Astral Flow also grants the Summoner the ability to summon Alexander and Odin if they have forged pacts with them. Alexander and Odin may only be summoned while the Summoner has the effect of Astral Flow.

The amount of MP required to cast the AFBP depends on the Summoner's level (specifically, twice the Summoner's current level). If the Summoner does not have the required amount of MP, the avatar the AFBP cannot be used. No matter how much MP the Summoner has, it will be reduced to 0 upon a successful casting of an AFBP. With the proper items and/or equipment, a Summoner may use up to three AFBPs per Astral Flow use, making this ability useful in many special battles and Burning Circles.

v · e · dFinal Fantasy XI Abilities
Bard	Critical Defense Bonus - Fencer - Soul Voice - Nightingale - Pianissimo - Resist Silence - Troubadour - Tenuto
Beastmaster	Amorph Killer - Aquan Killer - Beast Affinity - Beast Healer - Bird Killer - Call Beast - Charm - Familiar - Fencer - Feral Howl - Fight - Gauge - Heel - Killer Instinct - Leave - Lizard Killer - Plantoid Killer - Ready - Resist Amnesia - Resist Slow - Reward - Sic - Spur - Stay - Stout Servant - Tame - Vermin Killer - Wide Scan
Black Mage	Clear Mind - Conserve MP - Elemental Celerity - Elemental Seal - Enmity Douse - Magic Attack Bonus - Magic Burst Bonus - Manafont - Mana Wall - Occult Acumen
Blue Mage	Assimilation - Azure Lore - Burst Affinity - Chain Affinity - Convergence - Diffusion - Efflux - Enchainment
Corsair	Rapid Shot - Resist Amnesia - Resist Paralyze - Double-Up - Fold - Loaded Deck - Phantom Roll - Quick Draw - Random Deal - Rapid Shot - Snake Eye - Triple Shot - True Shot - Wild Card - Winning Streak
Dancer	Closed Position - Conserve TP - Critical Attack Bonus - Dual Wield - Evasion Bonus - Fan Dance - Flourish - Jig - Presto - Resist Slow - Saber Dance - Samba - Skillchain Bonus - Step - Subtle Blow - Tactical Parry - Trance - Waltz
Dark Knight	Arcana Killer - Arcane Circle - Arcane Crest - Attack Bonus - Blood Weapon - Critical Attack Bonus - Desperate Blows - Last Resort - Muted Soul - Nether Void - Occult Acumen - Soul Eater - Tactical Parry - Weapon Bash
Dragoon	Accuracy Bonus - Ancient Circle - Angon - Attack Bonus - Call Wyvern - Conserve TP - Critical Attack Bonus - Critical Defense Bonus - Deep Breathing - Dragon Breaker - Dragon Killer - Empathy - High Jump - Jump - Restoring Breath - Smiting Breath - Soul Jump - Spirit Link - Spirit Jump - Spirit Surge - Strafe - Super Jump
Monk	Boost - Chakra - Chi Blast - Counter - Counterstance - Dodge - Focus - Footwork - Formless Strikes - Hundred Fists - Impetus - Invigorate - Kick Attacks - Mantra - Martial Arts - Max HP Boost - Penance - Perfect Counter - Skillchain Bonus - Subtle Blow - Tactical Guard
Ninja	Dual Wield - Futae - Innin - Magic Burst Bonus - Mijin Gakure - Ninja Tool Expertise - Resist Bind - Sange - Skillchain Bonus - Stealth - Subtle Blow - Tactical Parry - Yonin
Paladin	Auto Refresh - Chivalry - Critical Defense Bonus - Cover - Defense Bonus - Divine Emblem - Fealty - Guardian - Holy Circle - Invincible - Iron Will - Rampart - Resist Sleep - Sentinel - Sepulcher - Shield Bash - Shield Defense Bonus - Shield Mastery - Undead Killer
Puppetmaster	Activate - Critical Defense Bonus - Evasion Bonus - Fine-Tuning - Martial Arts - Optimization - Overdrive - Repair - Resist Amnesia - Resist Slow - Role Reversal - Stout Servant - Tactical Guard - Tactical Switch - Ventriloquy
Ranger	Accuracy Bonus - Alertness - Barrage - Bounty Shot - Camouflage - Conserve TP - Double Shot - Eagle Eye Shot - Flashy Shot - Rapid Shot - Recycle - Resist Poison - Scavenge - Shadowbind - Sharpshot - Snapshot - Stealth Shot - True Shot - Unlimited Shot - Velocity Shot - Wide Scan
Red Mage	Chainspell - Clear Mind - Composure - Convert - Fast Cast - Magic Attack Bonus - Magic Burst Bonus - Magic Defense Bonus - Resist Petrify - Saboteur - Shield Mastery
Samurai	Blade Bash - Demon Circle - Demon Killer - Hamanoha - Hasso - Ikishoten - Meditate - Meikyo Shisui - Overwhelm - Resist Blind - Seigan - Sekkanoki - Sengikori - Shikikoyo - Skillchain Bonus - Store TP - Third Eye - Zanshin
Scholar	Addendum: Black - Addendum: White - Clear Mind - Conserve MP - Dark Arts - Enlightenment - Libra - Light Arts - Magic Burst Bonus - Max MP Boost - Modus Veritas - Occult Acumen - Resist Silence - Stormsurge - Strategems - Sublimation - Tabula Rasa
Summoner	Astral Flow - Assault - Auto Refresh - Avatar's Favor - Blood Boon - Blood Pact: Rage - Blood Pact: Ward - Clear Mind - Elemental Siphon - Mana Cede - Max MP Boost - Release - Resist Slow - Retreat - Stout Servant
Thief	Accomplice - Ambush - Assassin - Assassinate - Assassin's Charge - Aura Steal - Collaborator - Conspirator - Critical Attack Bonus - Despoil Dual Wield - Evasion Bonus - Feint - Flee - Gilfinder - Hide - Mug - Perfect Dodge - Resist Gravity - Sneak Attack - Steal - Treasure Hunter - Trick Attack - Triple Attack
Warrior	Aggressive Aim - Aggressor - Attack Bonus - Berserk - Blood Rage - Critical Attack Bonus - Defender - Defense Bonus - Double Attack - Fencer - Mighty Strikes - Resist Virus - Restraint - Retaliation - Provoke - Savagery - Shield Defense Bonus - Shield Mastery - Tomahawk - Warcry - Warrior's Charge
White Mage	Afflatus Misery - Afflatus Solace - Auto Regen - Benediction - Clear Mind - Devotion - Divine Benison - Divine Caress - Divine Seal - Divine Veil - Martyr - Magic Defense Bonus - Shield Defense Bonus