User blog comment:The Smarter, Wiser King Dedede/The most thought-provoking question on this wikia/@comment-33001101-20190928001545

The Loud family are placed in a situation where they would have to sacrifice someone or 2 people. ¯\_(ツ)_/¯

They would choose Luna because she doesn't have many characterisation qualities so whatever and Leni would volunteer because she believes that she is selflessness and she believes in good will because she doesn't want to someone, but chose herself as a non-selfish way.