Titan Serum

Lore & Background

The creation of Pure Titans relies on injecting Eldians with Titan spinal fluid, converting them into the weakest and most common type of Titan. These beings exhibit predictable behaviors but remain dangerous due to their relentless attack on humans. The source clarifies that if a Pure Titan consumes a human possessing one of the Nine Titans—such as the Attack, Colossal, Armored, Female, Beast, Jaw, Cart, War Hammer, or Founding Titans—that Eldian reverts to human form and gains the Shifter's specific abilities. This transfer is bound by a curse: the new holder lives only 13 more years. If a power holder dies without passing their ability to another through consumption, the power transfers to an Eldian baby born shortly thereafter, regardless of distance or blood relations.

In Their Own Story

During the conflict within Wall Rose, Ymir revealed her ability to transform into the sentient Jaw Titan after consuming a Pure Titan. Later, Rod Reiss attempted to force Historia to ingest a vial of spinal fluid made from Titan fluid so she could eat Eren and reclaim the Founding Titan's power. When Historia refused and broke the vial, Rod consumed the serum himself, transforming into a monstrously large Abnormal Titan that mortally wounded Kenny Ackerman before being killed by Historia. In another pivotal moment, after the battle of Shiganshina, Levi injected Armin with a serum given by Kenny, causing Armin to eat Bertholt Hoover and gain ownership of the Colossal Titan. These events confirm that the combination of spinal fluid injection and consuming a shifter's flesh is the only way to inherit the Nine Titans.

Reader's Guide

First, injecting an Eldian with spinal fluid from any Pure Titan or non-holder source results in a mindless Pure Titan transformation. These entities are easily killed but pose a constant threat due to their numbers. Second, to inherit one of the Nine Titans, the injection must be paired with the consumption of a current Shifter's flesh and spinal fluid. This specific ritual allows the recipient to revert to human form while gaining the Shifter's powers and memories. Without this consumption step, the serum only creates a mindless beast. Additionally, if no eligible heir consumes the power within 13 years of a holder's death, it automatically passes to a newborn Eldian.

Did You Know?

• If a power holder dies without being consumed by another Eldian, their Titan ability transfers to an Eldian baby born shortly after, regardless of distance or blood relations.
• Eldians who become Pure Titans through spinal fluid injection can only revert to human form and gain Shifter powers if they consume the flesh of one of the Nine Titans.
• The transformation into a mindless Pure Titan occurs simply by injecting an Eldian with Titan spinal fluid, without the need for consuming another shifter.
• Every holder of the Nine Titans is cursed to live only 13 more years after gaining their powers.