Castiel felt intensely proud of Ben in that moment, and he knew Dean would feel the same when he was back. Because he would be back, there was no other acceptable option.
They would get through this, all of it. They had to. Castiel would find a way to make everything right again and not leave Ben without a family.
He didn't say anything at the way Ben rubbed at his eyes, sensing that maybe he had inherited his dad's habit of not wanting to acknowledge 'chick flick' moments. Instead he just nodded, concentrating for a moment before they both vanished, reappearing at street just outside the Winchester house, as close as the angel could get with all the wards in place.
"Here we are," he nodded again. "She's going to need you more than ever right now."