>>162
I don’t think you understand Legatos' character well at all. You’re trying to take everything they do in isolation, but all of Legato's actions are taken in relation to the unfolding situations that are Vash and Knives. Legato tortures Vash for the sake of Knives, his dream, and his affection for Vash. That certainly isn't NOT a reason. Legato wants vengeance upon Vash for almost killing Knives with his angel arm in July. A desire intensified through his love for Knives. And despite having left Knives for dead twice, Legato lives with the constant awareness of Knives' persisting preference for Vash grafted onto his flesh. The right arm that hangs at his side was once Vash’s and so is at once both what allows him to reside at the side of his beloved Knives, and a reminder that the position he holds is only through the wound created by Vash’s rejection of Knives. The loss of the arm is a wound central to the relation of Vash, Legato, and Knives. Betrayal and disappointment, the agony of never having your affections be returned. Legato plays host to a very special kind of hatred for Vash, and unleashes a very specific brand of violence because of this. Unable to eliminate Vash without destroying something the one he loves would not do without Legato proceeds by inflicting psychological torture upon the stampede. Able to kill anyone but Vash, Legato places the target on Vash’s refusal to take any life whatsoever. Not because it is something so valuable to Vash that he would become a mere shell of himself without it, but because this is the value that separates Vash and Knives to begin with. To remove it from Vash allows for the reunion of the man Legato loves with the brother he desires. In a certain sense then Legato's actions sing out a love for Vash as well as Knives. Reaching in and killing a piece of Vash which keeps him from being with someone they both care for. Gently coaxing him toward pulling the trigger, “it's alright kill me '' and making sure he can't excuse it away by saying he was forced into it “don't make me!” “you have free will, time to choose”. Creating a trap for Vash to act on his value for Milly and Merlys life over Legato’s own is the first step in transforming Vash into someone that can be with Knives in the way Legato wishes he could be. His death becoming the connective force between Knives and Vash, becoming a piece of Vash that will carry him to Knives. Vash’s collapse was an unintended consequence, a result of a failure to fully abort his insistence on upholding Rem’s morality, though decimating him and forcing him to become something different was certainly intentional.
A villain like Legato simply couldn't exist without an idealist like Knives.