Power Crisis

Everyone has their own unique power. Families have two, even divorced families, or orphaned children. The only expeditions to the two power rule, are twins, triplets, quadruplelets, any form of sibling that were born practically at once and shared a womb at the same time. They have three, their unique power, their family power, and their power they share with their twin(s).
People's secondary power, their family power, changes over the course of time depending on their love. Children's family powers will remain the same, even if they're familyless or if their parents have split, until they fall on love.
Once in love, both partners attempt to decided together on a power they want to share. If the gods decide it is unique enough, they get the power they chose, if not, the gods decide for them. It's a basic cycle with a hard outcome.
If one falls out of love, their power returns to the original power of their family. If they're in a one sided love the same thing happens. It's the gods way of trying to save both parties before it is too late. It's the only hope for people in an impossible love.
People are born with their powers represented on their hands. If they have three, their sibling shared, and family shared power are on their weaker hand (unless said person is ambidextrous, then it is simply on their left hand). The person's sibling power is represented on a larger scale, while their family power is represented in a smaller way. Their unique power is on the hand they use more often (once again, if they're ambidextrous it's in their right hand).
The symbols to show their powers are straight forward and always on the back of their hand, easy to see unless covered up.
Some unique powers are also shown in a different way. For instance, if someone controls fire, a tiny, harmless flame will always be evident on their head.