Um... I have never seen anyone catch a lightsaber with their mouth and proceed to spit blaster bolts at them.
But keep telling yourself that.
Of course you have not, simply because this part of Lord Emperor's abilities is still in production. Lord Emperor was also able to drink plasma from lightsabers and then transfer it under his finger nails to create legendary technique " Tenth blade of Korriban " - "tenth" because the final move was always a strike with a right thumb into eye socket.