1. Character Birthdays: Every characters (except Double) has a birthday, the suggestion is an special event (1-day only) for all characters. Other mobile games usually only give gifts to the users on those dates, but skullgirls can go one step further and design personalized event for the characters. 2. Max Level "Reward" (Gold only): I can't confirm this, because I don't have any Max Lv Gold character, but it would be nice listen a small conversation with the character as reward. Different conversations for every version of the characters would a very interesting feature and a nice motivation to upgrade even bronze units.