Challenge Mode/Blackest Night Martian Manhunter/Standard/Challenge Battle 5

Lex Luthor is required for all matches in battle 5. All versions of him are viable, although Lex Luthor/Krypto is clearly the strongest choice.

Challenge battle 5 is generally regarded as the hardest battle on standard difficulty. It can mostly be done with normal gold cards (without promotions or good gear), but it will take a lot of practice and luck.