You fall asleep and find yourself dreaming of a room filled with mirror's. A voice tells you each power the mirror grants:
Space and Time - The grants you space and Time manipulation
Fantasy and imagination - All powers fantasy and imagination Manipulation
Sun and moon - All powers related to the Sun and Moon
Heat and Cold - All powers related to heat and Cold
Light and Darkness - All powers related to Light and Darkness
Nature and Elements - All powers related to Nature and the Elements
The shared weakness all the mirrors have are that you can't use one set powers in excess of the others. (If you've seen it think Shoto from My hero academia)
A lot of these overlap. There's really only 3 option, Time and space, Nature and Elements, and imagination and fantasy. With that being said, i would choose Nature and Elements