Segiri

No. 7, named Segiri by Sena, is a Hero in Xenoblade Chronicles 3. She is the commander of the mysterious Colony 0 and pilots a mech called a Ferron.

Inhumanity
No. 7 and several Ferrons attack the party on multiple occasions. She was properly introduced during Inhumanity. While fighting the party at Captocorn Peak, Sena damaged her Ferron, knocking her unconscious. When the party examined the damaged Ferron's cockpit, they were shocked at how young she was. Eunie suggested to take her to get treatment, with Noah adding to take her to the City, and Taion agreeing with him.

Other appearances
Segiri is required to be in the party for the Quests, In Search of a Home.

Segiri can be among the recruited Heroes to aid the party in the final battle against Z, commencing her final mission as she is summoned. After Z's defeat, despite not being affiliated with either Keves or Agnus, Segiri can be seen on the Kevesi side as Aionios splits back into the two worlds it was created from.

As a boss

 * No. 7 (boss)

As an NPC
Segiri can be found at Colony 0 when not engaged as the party's Hero. After completing the quest In Search of a Home she can be found at Li Garte Prison Camp.

Trivia

 * According to concept art, Segiri's term mark is on her right forehead.
 * Segiri is the youngest Hero.