Suzi Endo's past is unknown before she started to work at Stark Industries East Division as head of the Cybernetics department. All of Suzi's work and research was destroyed when the Avatars of the Mandarin attacked Stark Industries. Luckily Suzi survived and was found by Force Works who had also stopped the Avatars of Mandarin. They brought her back to their headquarters, where she started helping Iron Man by working on a techno-organic virus that Iron Man could use to defeat the Mandarin.
Suzi Endo was created by Dan Abnett, Andy Lanning and Tom Tenney and first appeared in Force Works issue 6 (1994).
Major Story Arcs
The Hands of the Mandarin
After the techno-organic virus succeeded and Iron Man defeated Mandarin, Suzi headed to Hong Kong to begin research. Suzi came back to United States, months later, when Iron Man proposed a job proposition for her to work at Stark Industries. Her future-self, Cybermancer of Earth-9528, then attacked Suzi and was moved to the Force Works sub-basement. Cybermancer took Suzi's identity and was presumed by everyone to be the present Suzi. Century who had been gone was then replaced by Cybermancer, Iron Man had helped in this but was being controlled by Immortus (who was posing as Kang the Conquerer at the time).
Amanda Chaney later found the real Suzi and told Rachel Carpenter about Iron Man betraying them. Rachel was then killed by Iron Man. Suzi was finally freed when some of the Force Works members battled Iron man and Cybermancer and won. In a brief conversation between Suzi and her future-self Cybermancer, she was told that she would grow to become just like her and no matter what she did, she couldn't change it.
Briefly, a time portal in the lab opened and Ultron and her current lover Wonder Man came through looking for Cybermancer. They broke Cybermancer out of prison and then went in search for her suit. Unknown to to them, the real Suzi took the suit from its storage container and hid it so that they couldn't find it. It was later revealed by Force Works that the timeline that fake Suzi, Ultron, and Wonder Man had came from, had been destroyed. So they decided to stay in this timeline and to live on Earth.
The gateway to the alternate world was still open even though the world was destroyed. The alternate Suzi and Ultron died when they entered the gateway to their world, then Wonder Man died while attempting to close the gateway by jumping into it but the portal wasn't closed until the real Suzi sent the Cybermancer Suit through the portal by using its gauntlet to control it.
Suzi fulfilled her destiny told by her future self, when she engineered her own Cybermancer armor. For a while she wasn't heard of until she was captured by S.H.I.E.L.D agents during the Civil War. S.H.I.E.L.D was trying to keep a bank heist from happening but they failed and a total of three citizens were killed.
During the Secret Invasion, the Avengers were attacked while in the Savage Land and Tony Stark and his Starktech systems were compromised, so Suzi joined with Jim Rhodes to help fight off Skrulls. Suzi than was revealed to be part of the Iowa Initiative team.
The Seeker of the High Evolutionary
Suzi then got a job working with the United States Army for her technical abilities and knowledge of extra terrestrials. This would bring her in to contact with the Silver Surfer, who was stripped of his powers before her eyes. He became captive of the Army and subject of Suzi, but she decided to help him escape and assist him in stopping the High Evolutionary and returning his powers.
They were able to sneak on board the stolen star ship that the High Evolutionary was using to spread and perfect life on Earth with. But Galactus' level of technology on the ship seemed to put Suzi in a trance. The High Evolutionary arrived and made his plans known. He would travel the universe and supply life to dead planets, much the opposite of Galactus. In order to do so, he required a herald. He chose Suzi and infused her with the Power Cosmic, changing her in to a new being - The Seeker.
However, this led to a conflict between the High Evolutionary and Galactus, and the High Evolutionary abandoned Suzi. The Silver Surfer wished to remain with Suzi, but was duty-bound to take up the role of Galactus's herald once again, and Suzi was left stranded by herself, seemingly stripped of her power. She was then returned to earth by the Fantastic Four.