I recently finished the comic, it is a very good read but I feel like Eve is quite underutilized in the story. She is basically a depowered Dr. Manhatten but the story treats her like a typical superhero girlfriend for the most part. Early in the comic and in her special it is revealed that her power is only limited by her psychological restriction and she can turn into super saiyan in near-death experiences. It felt like a Chekov Gun but it is only brought up again in the very end of the comic for a comedic moment. She is also revealed to be a science genius and was never brought up again.
I feel like Eve’s five years in the Coalition should help her to explore the potential of her power and become well prepared for the 2nd Viltrumite War. And she should have a badass moment in the final arc instead of throwing useless pink things. Hell, the writers could even create some dramatic tension by giving Eve a countdown for going into deus ex mode, like she could only hold it for five minutes or else she could DIE, something like that.
I wouldn’t say the depiction of Eve is sexist in Invincible, and to be fair the series in general is never interested in having creative use of superpowers and abilities, and the treatment is not exclusive to Eve or female characters. Basically every Earth superhero except Robot (and Eve) is inconsequential to the major plot of the story which is the Viltrumite war, which I think is the kind of the point of the story.