Do you know where people got the powers heating, freezing and control/molding from? I do. From the Earth, Luna and the sun.

Earth: Is for the control/molding since it hass so much water that there are wves and currents. That's all mermaid magic control/molding.

Sun: That it is hot and it heats up everything around that's how the heating power comes into play.

Luna (Moon): The moon has heard that it's possible that it has a frozen crust underneath it. So it's freezing power.

It's all true no lie I didn't look it up on the web but I know because I love astronamy that I know everything about this stuff practically.