Deals dark damage that weakens an enemy's attacks and gradually reduces its HP.


Spell cost: 36 MP
Spell element: Dark
Magic skill: Dark Magic

Note: Automatons learn this spell automatically once they have the requisite magic skill. They do not need to use a scroll.


Casting Time: 1.5 seconds
Recast Time: 5 seconds

Other Uses

Resale Price: ~2,050 gil

How to Obtain

Auction House Category: Scrolls > Black Magic ( )


Name Location Price
Chutarmire Selbina (H-9) 12,600 - 14,560
Hilkomu-Makimu Windurst Waters South (G-7) 12,600 - 14,560
Mazween Aht Urhgan Whitegate (G-7) 14,000

Note: Hilkomu-Makimu sells Bio II to Windurst Citizens only when Windurst is 1st (Conquest).

Other Information

Bio II duration
40 tics in 120 seconds. (2 minutes)
Bio II Damage Tiers and max dot-dmg (not counting inital dmg)
Dark Magic Skill ??? - 210 = 5/tick = 200
Dark Magic Skill 211 - 250 = 6/tick = 240
Dark Magic Skill 251 - 290 = 7/tick = 280
Dark Magic Skill 291 - ??? = 8/tick = 320
Enemy Attack down effect
Attack is reduced by 26/256 (~10.1%)
April 3, 2019 Version Update
"The attack down effect of the black magic spell Bio has been adjusted. Numbers in parenthesis represent the value when affected by the Corsair ability Dark Shot.
Name Pre-adjustment → Post-adjustment
Bio 5% → 10%(13%)
Bio II 10% → 15%(18%)
Bio III 15% → 20%(23%)"
Dia / Bio Priority 
Dia and Bio do not stack. Since Light and Dark are in opposition, whichever spell is higher level (requires a higher level job to use), overwrites the other.
Bio III > Dia III > Bio II > Dia II > Bio > Dia
Example: If Dia is cast, and Bio is cast afterwards, Dia will be overwritten. If Dia II is then cast, Bio will be overwritten. If Bio II is cast, Dia II will be overwritten.
Dia and Bio also do not overwrite themselves, so casting the same spell multiple times will not extend the duration of the effect.