A Balor's body was unable to channel mana. It was one of the reasons why millennia ago such a powerful race had attempted to force their evolution and ended up joining the ranks of the Fallen races.
Unlike all other creatures, they could conjure spells only through their eyes, making it vital for them to always face their opponents. Their other biggest limitation was their inability to cast spells above tier three.
The highest tiers of magic required to fuse and manipulate multiple elements at will, while each one of the Balors' eyes could only handle one specific element. Activating more than one eye at a time was possible, but they were unable to cooperate.
The only exception was the creation of hard constructs, like weapons or armors made from ice. They could be infused with multiple elements, but always one at the time.