The Custodian

 is an ex-member of the Cauldron staff.

Personality
Considered herself duty bound to protect the Cauldron Compound and act as warden for the people there.

Tried to be relatively gentle when dealing with Cauldron subjects. Not using lethal force when actually able to.

Relationships
As she was unable to communicate with most people given the state she is in, she was just another silent tool Cauldron used to achieve their ends. Yet she is still able to use her abilities to communicate with The Number Man, Satyrical and Taylor  each developing ways to give a 'voice' to the voiceless woman.

Appearance
The Custodian's bodies are made up of insubstantial invisible air, undetectable to most human senses, making her presence known through her actions and similar. Some people can sense her presence or attention easier then others however.

As a Titan she is one of the bigger ones, as her palm-prints suggest, she dwarfs the Titan Ophion by several orders.

Abilities and Powers
The Custodian is a parahuman made of air, invisible and almost completely incorporeal. She is bound to the Cauldron complex occupying the entire structure, essentially omnipresent except in a few key areas.

When she manifests her powers she is shifting where her focus is and incarnating temporary duplicates of herself. She can do this in enormous numbers, which she can either use for combat or to patrol Cauldron's base. She can use her abilities to manipulate objects with heavy or delicate force. Serving as a viable counter and containment measure for the innumerable Deviant cases that Cauldron houses and one-woman maintenance staff.

Her power is limited in application mostly by her attention span or cramped environments.

She is capable of pulling herself back into a human form, but chooses not to the majority of the time.

After Titanification her power was scaled up, allowing her to toss whole buildings at once.

Background
The Custodian was originally a Earth Cheit native, who was given a Cauldron Vial.

Despite the horrendous wrong done to her she voluntarily, of her own free will, took on a role in Cauldron.

Post-Echidna
The Custodian assisted Number Man in preventing an escape by Subject 3016.

She later provided silent invisible security at the Khonsu Meeting where a new world order was forged. She presumably provided similar security for subsequent meetings.

Gold Morning
May have also been at the meeting to discuss Zion's rampage.

Was held off by the Irregulars through the use of Mantellum.

Assisted both Taylor's assault team and Vegas Dark in finding Doctor Mother.No. Wait. There was someone. Something. I’d sensed it at the meeting the Doctor had arranged. The spirit, the ghost. So subtle it was almost impossible to notice. The currents of the air, the faintest of traces in dust that marked where she’d traveled… all things I’d mentally dismissed. Air tended to move. Only the fact that this was a closed space, without any kind of air conditioning or temperature difference made the movements in the air curious. Paying attention, I could see that there was a pattern, a consistent repetition in air currents so feeble they might not have moved a feather. The lights flickered back on, went out, and then settled in a compromise, the dull translucent pane of the ceiling lit up with a patchwork of maybe two thirds dark to one third light. “We’re here to help,” I called out. My voice echoed down the hall. “I thought you didn’t sense anyone,” Canary said. “I don’t,” I said. “Then who are you talking to?” “I don’t think it’s a who,” Imp said. “Try ‘what are you talking to?'” “Shh,” I bid them to be quiet. I could sense more movements in the air, close… no. That was a result of Lung’s fire heating the air. Further down the hall. If I use enough bugs, try to get a sense of dimensions… A head, part of a torso. I could feel the contours of narrow shoulders, the waist. Female. She disappeared, or she became less coherent, the movements in the air continuing, but ceasing to suggest a general human shape. Another appeared behind us, roughly as far away. No arms, no legs. Just a broken figure. “Help me out, Tattletale?” I asked. “Help with what?” “The Custodian.”  “I’m not getting anything usable,” she said. “Video cameras suck like that.” “Right,” I said. Louder, I called out, “We’re here to help the Doctor! You’ve got two other groups in here, one that’s definitely hostile, angry and destructive, and another I think is worth being suspicious of.” A movement, a reaction to that last sentence. I explained, “Maybe they seem friendly, but they’ve got a bad history of backstabbing, making subtle plays for power. I think the Doctor would back me up on this. If she’s cooperating with them at all, she’s doing it with knowledge they’ll capitalize on any weakness she shows… and she’s never been weaker than she is right now.” The figure turned around, briefly fading out of existence. She reappeared in a way that made me wonder just how long she’d been there, a foot away from me. “We’re not your enemies,” I said, holding my ground. “I want to stop Scion, and the best, easiest way to do that is to get things back into working order here.” For an instant, she was in four places at once. Then she settled on three. It struck me that I’d never fared particularly well against stranger-class powers. “If it helps,” I said, “I’m pissed. The Doctor called you the Custodian, which probably means you’re the one taking care of this place. If you’re not completely emotionless, it hurts, that they’re tearing it apart. If you care about the doctor, I’m betting you’re worried. Maybe you feel like I do. You want to retaliate, but something is getting in your way-” And then she was gone. - Excerpt from Venom 29.4 Was able to contain the escaping Case 53s and invading Irregulars when Mantellum was removed.

Post-Time Bubble Pop
With Teacher having moved into the old Cauldron base, the Custodian has started working with him and was re-named as the Overseer.

The Overseer assisted in the project to undermine the heroes of Earth Gimel through digital means.

She fought Breakthrough and The Heartbroken during their attempt to free Contessa. After failing that, she collapsed the section of the complex to prevent their advance.

At the end of the battle she retreated to Earth Cheit alongside Teacher.

The Ice Breaks
When reality broke for the second time, the Custodian was transformed into a Titan. She quickly made her way to Titan Fortuna to support her side, but was being denied the opportunity to wreak havoc there by Dragoncrafts. She delivered her revenge by destroying Defiant's Uther.

The Custodian Titan protected Titan Fortuna from The Simurgh.

Trivia

 * Despite speculation, the Custodian has no connection to the fate of Manton's daughter.
 * While Custodian in its modern usage refers to a keeper or cleaner one of its earlier meanings was guardian.