Talk:Challenge Mode/@comment-39.48.31.108-20160612111016/@comment-28140789-20160612112249

When you complete a challenge character's challenge (regardless of whether you skip zero or all battles therein), you can then directly promote that character for its own price; you do not have to complete its challenge again to promote it (although this can save you credits), nor do you have to obtain copies of it in a pack. Obtaining copies of a challenge character in a pack will not unlock it for direct promotions.

This has all been historically true, save during the 2.8 update. All new characters of 2.8 are not directly promotable (this is the Dawn of Justice characters, Antimatter Sinestro, and Black Adam Kahdaq; Batman/Dawn of Justice was not a challenge character, however).