[catwhowalks]

I see this as entirely within character. Kento isn't evil. He doesn't want to hurt anyone. He just genuinely believes the swords will destroy the world. Saving Sophia does not in any way compromise that mission.

Speaking of which I have a theory that Kento and both of the previous Calibers have a fundamental misunderstanding of what the visions of the future mean. They think they are showing them what WILL happen. I think they the visions merely show everything that can go wrong. All his visions show the world being destroyed because of the swords because it's only showing the bad outcomes and not all the countless good ones where the swords save the world instead. The visions are meant to show the wielder what to avoid doing, not what to do. It's a sword of darkness after all, so it makes sense that it can see only the dark outcomes.

I think we even already saw a hint of that, when he saw Primitive go on a rampage, but Touma de-henshined instead after befriending the dragon. That was a good outcome, so he never saw it.