Its pretty clear thats the intention if you want it to play it that way.It almost makes me wonder if devs planned some kind of redemption arc for Kas and don't want her to do actually evil things on screen to make this redemption easier for players to accept.
From the very start you have two paths, refered to by the Devs as the Rival and Romance paths. This is most obvious in the Winter city dungeon where it completely changes the outcome of events (in a way I HIGHLY suspect they will regret latter), but can be seen elsewhere in the game.
Romance Path: Aileh comes through and screams at Kas to close the portal. She fails to do so and an 'Abyssal Thing' comes out of the portal and corrupts 'Dragon daughters' except Aileh. You then proceed to fight the Abyssal thing and get your arse handed to you until the gods intervene to defeat the Abyssal thing. You then mop up the remaining corrupted dragon daughters.
Rivalry path: The Abyssal thing doesn't exist AT ALL, and the portal is instead destroyed by a bolt of Lightning (implying divine intervention), limiting how many Dragon Daughters get through. Regardless however, Kas orders the Dragon daughters to kidnap Elven nobility and then leaves.
We know that Kas overall goal (at least in the Romance path) is to have a child of their own, which will require their soul to be restored (you need to build the Temple to Mallach to find this out). Its possible that the Rival path is the same... but the fact she has an army and victims in that path means she might have other goals or motivations.
The problem of course is that the devs naturally don't want to write 2 entirely different games, YET these two differently described Kas's would treat the world differently. So they have collectively ignored the issue, which has the consequence of making it appear like the Romance Kas is the real path.
From my perspective I would not be surprised if long term Kas is dropped as a victim and Tollus becomes the new big bad. Whether the Devs will even remember Kas kidnapped a bunch of elven nobility and has an army of dragon-daughters when we come to the final dungeon....
Lets say I have doubts.
(Having said that I prefer the romance path from a self corruption perspective, BUT if I was doing the rival path I would be kinda frustrated. Kas as a true villian only really occurs at the start and at the Centaur villiage... maybe the Hornets if you stretch it... after that its really had to pinpoint a truly evil thing she has done.)