Wonder Woman places Lex Luthor under her lasso of truth and he admits that he’s an ego maniac, and being a hero by saving the world was always one of his dreams. Now he wants to join the Justice League since he sincerely believes Superman isn’t the primary threat to Earth anymore.
From – Justice League Vol 2 #30
That was a great scene!
The Luthor’s Redemption trope has been played with before in the DC Animated Original Version of All-Star Superman as I recall.
It always ends with the same result. But it never gets old. Haha