From what I understand the first quote is from The Witcher.
‘Geralt,’ said the lawyer, closing his eyes. ‘What drives you? If you want to save Ciri . . . I wouldn’t have thought you could afford the luxury of contempt. No, that was badly expressed. You can’t afford the luxury of spurning contempt. A time of contempt is approaching, Witcher, my friend, a time of great and utter contempt. You have to adapt. What I’m proposing is a simple solution. Someone will die, so someone else can live. Someone you love will survive. A girl you don’t know, and whom you’ve never seen, will die—’ "
Apparently in the original Polish they used pogarda, meaning a "mix of feelings of lack of respect, aversion and superiority over someone". (Reddit link.)
In English, then, they mean contempt as in "disdain and hatred for something". In this case, I understand that Geralt is going to be hated (by society? by himself?), and the lawyer thinks Geralt has to use that hatred against him as emotional fuel to find Ciri.
The second one is more straightforward. Contempt here more means "hate". It sounds like it means the speaker will get something, but only by doing something that will make them hate themselves.
Probably someone who's read The Witcher could make this clearer.
As was pointed out on that other question you linked, this is a surprisingly tricky sentence!
Let's slowly build it up.
It will take someone else.
What is "it"? Stopping Voldemort again. Implied but never directly said. As for "take", we could say "need" instead, just to be slightly clearer.
[Stopping Voldemort again] will [need] someone else.
This isn't "someone else" as in "we need a different person", but as in "we need other people prepared to do what you did, Harry". When will they be needed? "Next time" (that is, the next time that Voldemort tries to return).
[Stopping Voldemort again] will [need] someone else who is prepared to [do the same as Harry] next time.
Now, Dumbledore is saying that this someone else doesn't have to do much. Hence, it will "merely" (or "only") take someone else. This may sound like it's demeaning Harry's efforts, but it's meant to be reassuring Harry: standing up to Voldemort is not very difficult or unlikely after all, and it doesn't take someone extra-special to do it.
[Stopping Voldemort again] will merely [need] someone else who is prepared to [do the same as Harry] next time.
What, exactly, did Harry do that Dumbledore says they need other people to do (or be prepared to do)? "Fight a losing battle"--or what seems like a losing battle. (Dumbledore omits the word "like", but I'll leave it in for this one example.)
[Stopping Voldemort again] will merely [need] someone else who is prepared to fight a losing battle next time.
[Stopping Voldemort again] will merely [need] someone else who is prepared to fight what seems [like] a losing battle next time.
And now we just replace the bracketed bits with the different wording Dumbledore uses, and we have the sentence (okay, part of a sentence) that you bolded.
It will merely take someone else who is prepared to fight what seems a losing battle next time.
Best Answer
"A little while" is an idiomatic expression that literally means, "some relatively short amount of time", e.g.
As with many time-related expressions, the actual duration of "a little while" is pretty flexible, ranging anywhere from a few seconds to a few hours (or longer) depending on context: