Running is never an option and Alfin knew it better than anyone else.
He can't just stay and let Riber city fall. Not for the mistakes he made.
And the mistake was not making sure that Thalia was dead.
It was why he let the old man leave with the two prisoners of war. There was no need to inform this old baby and give Nephylite the chance from "stopping" him as well.
'This guy wants to revive his sister too much.'
Alfin understood the reason why he got this warning. He understood this clearly that Nephylite was not wrong for being selfish.
But there were certain things that a man had to do. It's what defines them, it's what makes them different from animals.
'Anyways, he will follow me on his own when he learns that I am gone. And on the battlefield, he probably won't be able to deny the request for help.'