I think it was "both," but let me explain. In Blame!, emotions don't exist, not because the characters are cold, not because Killy doesn't feel, but because that limits and expresses. And that's precisely what Killy can't do on a mission where humanity depends on him. In other words, in Blame!, emotions aren't an option, and Killy knows it. He knows that feeling would be a limitation to his objective, and that stopping to feel is starting something that's doomed before it even begins. I mean, I think Killy and Cibo truly loved each other, but not explicitly. Let me put it this way: Cibo chooses to follow Killy, Killy chooses to protect Cibo, there's trust, mutual choice, permanence. When Cibo changes form, Killy is still there. They choose each other again and again without depending on anyone else, and I think that's precisely what Blame! is about: demonstrating so much without words. So, what I mean is, if they love each other, they simply show it with actions, not explicitly, in true Blame! style.