I'd like to point out that killing Rollo would be a giant frickin' red flag with a big, bold arrow and the words, "I'm Zero! I'm back! Yes, it's me!"
You could very, very easily explain his reluctance to kill Rollo with that alone.
That's not to say I don't think he likes Rollo or anything. Actually, that point has nothing to do with their relationship at all. I just don't want to let ya'll read into something coldly strategic and call it feelings. He's trying to control Rollo because he can't let him act on his own, but he also can't just off him. "Using" him is his only real option.
Re: Lelouch and Rollo - Family bonds
You could very, very easily explain his reluctance to kill Rollo with that alone.
That's not to say I don't think he likes Rollo or anything. Actually, that point has nothing to do with their relationship at all. I just don't want to let ya'll read into something coldly strategic and call it feelings. He's trying to control Rollo because he can't let him act on his own, but he also can't just off him. "Using" him is his only real option.