Castor is an antagonist in Phantasy Star Online Episode III C.A.R.D. Revolution. She appears exclusively in the Arz main story penultimate quest, Final Battle. She and her sister Pollux are clones of Chief Red's deceased daughters.



Castor has the appearance of a teenager. She has blonde hair with lifeless, dull yellow eyes. The girl wears a blue helmet and matching blue body suit. There are two tentacles attached to her back which appear to be flexible appendages. The giant gun she carries with her is actually her grossly mutated left hand. Interestingly enough, it is not directly attached to her body since she can be seen dropping it when she falls in battle. Before firing a bullet from her arm, she bobs her head with enough force to move the aiming reticle attached to her helmet across her eye. After buffering the recoil from the shot, she moves the aiming piece back to its default position on her helmet.


Castor has no dialogue in the game. From what can be deduced from her boss battle posture, she appears to have deep concentration for the fight. She displays no emotion on her face beyond a dull, default smirk. This is in stark contrast to her highly animated battle stance.


In the Pioneer II government's bid for power, they officially sanctioned the Lab's research into bioweaponry by utilizing the mysterious Germ that was discovered on Ragol in AUW 3101. Seeing the potential for advanced bioweapons to assist the military, the lab cloned Chief Red's deceased daughters numerous times as fodder for its inhumane experiments that horrifically mutated their bodies into living weapons. Castor and her sister Pollux are some of the few that have been released following the discovery of the Great Shadow's location.

Castor confronts the Arkz anti-government organization, while Pollux fights the government's own Hunters. No matter the scenario, both girls inevitably fall to the hero in battle.

Powers and abilities

Castor card ingame low quality

Castor is the penultimate final boss of the Arkz storyline. She begins the fight with a hefty 45 HP. This character can easily make chances of victory become bleak if she is not subdued in as few turns as possible. Her armor allows her to negate any damage from attacks with strength less than 4.

Anti-Abnormality allows her to resist status effects, forcing Arkz to confront her directly with raw power. Two particularly dangerous abilities she takes advantage of are Haste, which gives her free reign across the small battlefield with no attack cost, and Carnage Uninclined, which allows her to attack the protagonist's HP directly even if she destroys summoned monsters. To make matters worse, her gargantuan firearm has a native 2 range that can be extended even further across the field with her Death Ray, Wave Motion, and Devil Whim C attack cards, essentially rendering escape futile.

Castor does have a weakness, however. Unlike Pollux whose strength increases each turn, Castor has the Steady Damage Mod which hurts her by 1 HP every turn until she has 9 or less health remaining. Although not a game changer to rely too heavily on, this penalty can assist the Arkz in defeating her on top of the damage coming from surrounding her with monster cards. Pouilly Slimes and Pan Arms prove especially effective at flanking her, however, great care needs to be taken if she moves in close enough to the protagonist to be able to use Cross Slay. A devious combo of hers is combining Dice Fever, which fixes all rolls to 5, and Devil Whim C, an attack that can cause instant death if a 5 is rolled. This makes it especially important to always pay attention to field effects during the fight when considering positioning, defense, and offensive strategy.

C.A.R.D. information

Castor's boss card can be viewed below. Top color is red. The combo colors on the right of the card are blue, red, orange, purple, and gray.

Card # Picture Resistance color Combo color left
Combo color right
Rarity HP AP Range
Name TP MV
N/A Castor card art ▬▬▬▬
N/A +25 6 Range2
6 2

———————————Single target attack

  • Anti-Abnormality
Prevents Abnormal Conditions: Acid, Drop, Freeze, Immobile, Paralysis, etc.
  • Carnage Uninclined
During an attack, an opponent Story Character loses 1 HP if this card destroys any card(s) that the opponent sets. Castor's special ability allows the opponent to lose more than 1 HP if multiple cards are destroyed with a single attack.
  • Haste
When this character moves, there is no ATK point cost.
  • Steady Damage Mod
Before the start of each of the card owner's turns, this Story Character loses 1 HP if this character has 10 or more HP.


Castor has only a single deck called Ice Heart. Its contents are as follows:

Ice Heart

Image Name Information
Pso2 no way NO WAY Acceleration 2 x3 When this card destroys an opponent, the equipper gains 1 MV. This ability only works once per attack. Cannot gain more than 1 MV from this ability. Functions similar to the Carnage Speedup ability.
Pso ep3 cross slay Cross Slay x3 This card attacks in all four cardinal directions next to the user (i.e. up, down, left, right).
Pso2 no way NO WAY Death Ray x3 A physical attack destroys an opponent who has the Freeze or Paralysis Condition. No effect against Story Characters. Functions similar to the Frozen Death and Paralyzed Death abilities.
Pso ep3 devil whim c Devil Whim C x3 This card produces various effects depending on the dice roll at the time of attack. 1 = Full heal to every Field Character on the field // 2 & 3 = AP Silence for 4 turns // 5 = Instant death
Pso ep3 dicefever Dice Fever x3 Fixes the dice roll of all players to 5 while this card is on the field. If two dice are rolled, both dice will roll a 5.
Pso ep3 dodge Dodge x3 Defensive action (HP +2)
Pso ep3 guard Guard x3 Defensive action (HP +4)
Pso ep3 reduction Reduction x3 Receive 1/2 damage from physical attacks. Damage taken after half is rounded down (eg. half of 3 is 1 instead of 1.5 damage).
Pso ep3 wall Wall x3 Team defensive action (HP +3)
Pso2 no way NO WAY Wave Motion x3 During a physical attack, the user of this card gains AP equal to the dice roll times 1.5. Functions similar to the Random AP ability.


Phantasy Star Online Episode III C.A.R.D. Revolution
Arkz Break - Lura - Creinu - Endu - Hyze - KC - Reiz - Peko - Ohgun - Memoru - Rufina - Rio
Hunters Sil'fer - Orland - Relmitos - Ino'lis - Glustar - Guykild - Kranz - Kylria - Viviana - Teifu - Stella - Saligun
Antagonists Leukon Knight - Castor - Pollux - Amplam Umbla
Locations Ragol - Pioneer II - Mortis Fons - Lupus Silva - Tower of Caelum - Ravum Aedes Sacra - Molae Venti
Morgue - Nebula Montana - Dolor Odor - Via Tubus - Unguis Lapis - Tener Sinus
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