I understand why you would be frustrated about it, but honestly there is a couple things to keep in mind if you didn't like what happened there. A: The dev put it there, so if anything you should be upset at that rather than a character that had one scene, and B: The only reason lore wise she even did what she did was because her boss told her to keep you in your cell, if she didn't extract your energy, you would have broken out, if you had broken out, her boss in her eyes would likely kill her or send her on a suicide mission, which is literally what happened Axius left her for dead because she couldn't hold us, which makes peoples hate towards her misdirected, they should be mad at Axius, not her, if Irena was the one holding us instead of her, she'd have likely done the same thing.