9'β

9'β (ナインベータ) is a character in DARLING in the FRANXX. He was a Parasite who served in the 9's, a special forces unit that APE directly controls. He was partnered with 9'η and piloted a FRANXX called 9 Model.

Appearance
Nine Beta has light blue hair swept over his right eye, and grey eyes. He wears a special Parasite uniform emblazoned with white and gold, instead of the typical gray uniforms that other Parasite squads use. When in his FRANXX, Beta, along with the others in his squad, sports a red battle suit. Like his fellow stamens, he appears with golden horns that appear to be holographic klaxosaur horns.

Personality
Nine Beta often does not say much and lets his team leader 9'α speak on behalf of the 9's squad.

In Episode 17, Nine Beta is shown to be aware of his surroundings as he commented the ruined state of Mistilteinn was not a good place for parasites.

In Episode 22, Nine Beta is shown to be willing to fight to his death when he, along with Alpha and Gamma, offered to come with Squad 13 to fight the final battle against VIRM. This was further demonstrated when he and Gamma went on 'a blaze of glory' in Episode 23 to take out a huge number of VIRM soldiers, where he met his demise.

Episode 06: DARLING in the FRANXX
Some 9's watch the battle (Alpha, Beta and Gamma) and 9'α says that Squad 13 is really hitting it off.

Episode 12: The Garden Where It All Began
Squad 13 meets the 9's, including 9'β while at the garden for tests. 9'β remains quiet as 9'α explains to Squad 13 they are at the garden for maintenance

Episode 14: Punishment and Confession
9'β stands with the rest of the 9's as Zero Two walks towards the cargo plane to leave Cerasus.

Episode 15: Jian
9'β and his partner 9'η are shown piloting in reverse positions. Despite the klaxosaurs mostly being Conrad-class and easy to kill, 9'β and his squadmates struggle at their huge numbers.

Episode 17: Eden
9'α, 9'β, 9'γ, 9'δ and 9'ε show up at Mistilteinn on Papa's orders. As 9'α explains that Papa hadn't forgotten Squad 13, much to their relief, 9'β whispers to 9'γ that the environment of Mistilteinn was not good for Squad 13. When offered bread by Zorome, 9'β politely declines. Later, 9'β and his squadmates examined the baby book 9'δ found when she bumped into Kokoro earlier and find it contains information that Papa has banned. At the end of the episode, 9'β and the rest of the 9's arrive at Cosmos by elevator. 9'α tells Papa there is something he needs to know.

Episode 18: When The Sakura Blooms
Kokoro and Mitsuru have a wedding, something Papa refers to as dangerous to APE’s objectives, so the 9's, including 9'β, lead an APE team on an assault on Mistilteinn. Zero Two attempts to fight off the 9's while Futoshi tries to protect the couple but they are outnumbered. Mitsuru and Kokoro are taken away to have their memories altered, as protocol.

Episode 20: A New World
The 9's and other parasite squads fight against the klaxosaurs when a new enemy, VIRM, appears. Squad 13 is confused and attacks VIRM instead after seeing the klaxosaurs stop attacking them and attacking VIRM instead. The 9's berate Squad 13 for not obeying Papa's orders at first but join in the confusion when squadmates 9'δ and 9'ε are killed by a VIRM soldier.

Episode 22: Stargazers
9'α, 9'β and 9'γ are shown to be in bad shape and lying sickly in hospital beds when Ichigo visits them. She mentions she heard they've been refusing to eat. 9'α explains that food can only abate their condition for so long and what they really need is maintenance. Ichigo knows that since Papa is not around the 9's cannot receive maintenance and sighs. She places their rations on the table and leaves. 9'α throws the rations and struggles to get up, cursing a little.

When Hiro is set to head for the Mars orbit for Strelizia Apath to reunite with Zero Two, Squad 13, 9'α, 9'β and 9'γ greet him. Squad 13 says they'll follow Hiro and help him get to Zero Two because they can't do anything if they don't fend off VIRM. 9'α says the 9's will help Hiro too because their home is the battlefield. 9'β adds that space doesn't seem too bad a resting place. Hiro is extremely grateful towards the support all of them showed in helping him reunite with Zero Two.

Episode 23: DARLING in the FRANXX
In space, 9'α, 9'β and 9'γ battle alongside Squad 13 against a massive number of VIRM soldiers. 9'β and 9'γ seem to be piloting alone as their partners 9'η and 9'θ are not shown. Following Squad 13's close shave with a bunch of VIRM, 9'α, 9'β and 9'γ jokingly remind Squad 13 they are fighting too. Ichigo referred to them as 'hospital runaways' and told them she wouldn't let them do all the hard work. After their leader 9'α heads straight for Strelizia, 9'β suggests going on a 'blaze of glory' to 9'γ. They blast through a whole bunch of VIRM, killing themselves in the process.

9's
Beta is loyal to his comrades and has no issue with them. He is willing to risk his life to protect them, as shown more authentically in the manga.

Etymology
Similarly to Zero Two, he received the name from Papa. Beta is a letter in the Greek alphabet.

Quotes
"Doesn't matter how many of you there are."

- Episode 15

Trivia
9'β 9'β 9'β 9'β
 * In the anime, Beta is killed while battling VIRM in space. In the manga, he is killed by the Klaxosaur Princess to give Alpha and Delta a chance to escape.