Hmm..No one but Tess knows what her character is, simply because we've seen too little of Astrid in the game and it's hard to get a sense of her character from her brief dialogue with Seth. However, from indirect hints in the game and from Tess' own words, Astrid is an idealist. Also, as we know, she is the only one who openly opposed Alexander Karlsson's tyranny, for which she paid the price. We also know that Astrid is very intelligent and brilliant in her own way, although not as brilliant as her sister Veronica. Astrid's genius lies more in the realm of creativity (whatever that means), though she is also a scientist. Either way, we'll just have to wait for ep8, and then hopefully we'll be able to get to know her better.
But the fact that Astrid made a strong impression on Kiyomi, who is generally hard to impress, speaks volumes. I'm guessing that Astrid will be a solid ally for GoodDom Kane and GoodOlivia. And I wouldn't even be surprised if her soul turns out to be untainted by sadism and cruelty..We'll live to see, though.