yeh u can, the best use of mime with a limit is barret's ungarmax.

this is a video of someone using ungarmax with 2 hero drinks, so each attack does 9999. then cos of the materia setup shown, when he uses mime ungarmax is used 8 times. and with 9999 each attack and 21 attacks in each limit . . . that's math i can't even do!!!

(21 X 9999) X 8 = poor emmy