Can you control when they are emitted? If so, it would be handy when outside in the cold. Otherwise... no.
Do I have a hypno-ray?
Downside? What downside? That's awesome!
Kind of like Destroyman from No More Heroes.
Since it says the words "at will" (which means you control when it happens....) then yes.
Ok so what so important about Mount Everest
Where should this comment appear?
This pairing only
Whenever "Gain superpowers allowing you to emit highly visible and flashy ..." appears
Whenever "Mount Everest ceases to exist" appears