Thanos was ruthless, even to his own children

The argument

Thanos "rescued" two children just to train them to be ruthless killers. From a young age, Thanos forced his two daughters to fight each other, inciting cruelty and an unhealthy rivalry between the two. He even replaced Nebula's body with mechanics as they went in order to improve her. What kind of father pits his children against each other? That action alone proves that he is a villain. No father, no matter what, should place that kind of cruelty on his children.

Premises

Counter-arguments

Thanos was simply doing what he had to do. He needed and wanted to raise strong children that would fight and work by his side without fail. He was doing what he needed to do.

Rejecting the premises

[Rejecting P1] Cruelty towards his adopted daughters establishes cruelty, which the opposing position does not deny; what is in dispute is whether that makes him a villain rather than a figure who does terrible things for reasons he takes to be necessary. The premise treats the two as identical and so assumes what it set out to show. [Rejecting P2] "No father should do this" is a claim about parenthood, while the conclusion is a claim about villainy in a story whose stakes the argument never mentions. Resting the whole case on the treatment of two characters also leaves out what the position is really about — what he does to everyone else — which makes this a weak route to the conclusion even for readers who accept it.