What would be the best thing to say, with this type of situation? A new hopefulness, to close off the gloom of the conversation?

Hmm.

... Ahh, I'm really not good at this.

"That is..." Minato started, "Probably the best way to show strength too."

He turns to Yugi with a nod, not entirely sure how he got all this philosophical with someone he was meeting for the first time, but might as well end on a good note. "Make your friends proud."