Samura's Plan MAKES SENSE NOW.

The plan of killing (and reviving, as happened with Chihiro and hopefully Uruha) the sword beares now makes sense, but it will require Samura's own sacrifice.

Thing is he doesn't hate the other sword bearers tk the point of KILLING them, he HAS TO kill them, to then revive them, in order to be able to finally kill the Sword Saint, who is the one Samura has a personal vendetta against for killing the Shokoku Island inhabitants even after they surrendered.

After this, none of the other sword bearers aside from Samura will suffer the wither curse, because he actually cares about them as sees them as friends.