Funnily enough about Luthor’s comment on “Mario doing something horrible to make Luigi hate him,” that couldn’t be further from the truth. IHY Luigi was just tried of Mario getting the spotlight, so he teamed up with Bowser to kill Mario and become more know, even though Mario still loved him just as much as in the original universe. And the winner of the worst brother ever award goes to IHY Luigi!
If you think about it, Luigi is also putting the lives of a whole kingdom at stake too. I mean, who’s to say Bowser won’t just kill Luigi after they were done with Mario? Or that Luigi would even protect the princess and the kingdom? If Luigi won, it won’t be just Mario’s life that would be lost