The Important MCU Character We Haven't Seen Since Age Of Ultron
In 2015, Avengers: Age of Ultron was released, the second time all the heroes would come together to save the world. In the film, Tony Stark (Robert Downey Jr.) and Bruce Banner (Mark Ruffalo), in an effort to prepare for any possibility of attack on Earth, craft a protection program intended to stay dormant until needed. After studying the Mind Stone from Loki's scepter, they find a form of artificial intelligence, and put it into a robotic creation they call Ultron. Not understanding the otherworldly capabilities of the stone, and believing they could manipulate it with science, the Avengers are surprised when Ultron gains sentience and reveals his own plan to save Earth — by killing all of humanity.
Ultron, voiced by James Spader, attempts to complete his plan, but first he wants a new body. So, Ultron then enlists the help of a scientist and friend of the Avengers, Dr. Helen Cho, played by actress Claudia Kim. Using the scepter to control Cho, Ultron utilizes her synthetic-tissue technology, alongside the Mind Stone to make a real body for himself. The Avengers are only able to beat Ultron by stealing the body back and uploading a new AI based on J.A.R.V.I.S., to be named Vision.
Now, after Avengers: Age of Ultron, the characters of Vision and Wanda Maximoff (Elizabeth Olsen), who is also introduced in this film, have continued on as fleshed out characters in the MCU, all the way to having their own upcoming TV show in Phase 4. However, as Comic Book Resources recently noted, the MCU left an important character behind — Dr. Cho.
World-renowned geneticist Dr. Helen Cho has been left behind ... for now
In the second Avengers film, Cho quickly establishes her skill and value by using her technology to save Clint Barton (Jeremy Renner) from what should've been a fatal wound, and once Earth is safe again, Maria Hill (Cobie Smulders) recruits Cho for scientific research at the New Avengers Facility ... but then, that's it. There's no further appearance or mention of the brilliant scientist. With her innovative thinking, Cho fits right in with characters like Stark and Banner, and logically, she should have returned as a huge asset to the Avengers, particularly during Infinity War.
Behind the scenes, it's also unclear why she hasn't come back. Her absence could be Marvel's decision due to an already crowded roster, or simply because of Kim being too busy: in fact, Kim actually had quite the packed schedule after the film, starring in the Netflix series Marco Polo, which ran from 2014 to 2016, before filming a whopping 50 episodes of the South Korean drama Monster. After that, Kim returned to blockbusters, with key roles in both The Dark Tower and Fantastic Beasts: The Crimes of Grindelwald, which was released in 2018. With all of that on her plate, it wouldn't be surprising if her schedule, indeed, hindered any chance of returning to the MCU.
Right now, Kim doesn't appear to have much coming up, and having appeared in other big studio films the past few years, maybe a return to Marvel — whether it be in a TV series or the films — could be on the tables. Considering that Dr. Cho is such a cool character, fans would definitely love to see her again.