take the planet constellation , add a new exo planet constellation , keep it the same to save extra graphix but exo planets have a blue heart instead of red , they have 0% drop chance , once a certain level of critical is achieved eg 25 or 50% then quests are given in mastery to give .01% for exo planets to appear ,these quests can also be rare, but heres the kicker exo planets are much stronger and only crit damage can hurt them therefore if you dont have enough damage or crit you have to rebirth because you cant damage exoplanet. thats one idea