Tifa’s Limit Breaks are somewhat different than those of other characters. She will use each of the Limit Breaks that she has in succession, either hitting, missing or getting a critical hit, depending on your success at the slot reels that appear when she first uses her Limit Break.
Each of the descriptions below mentions that the Limit Break hits one enemy, but each of her attacks will hit one random enemy on the battlefield as it cycles through the Limit Breaks that she has obtained.
You will also receive the Packing a Punch Trophy once you teach Tifa her Level 4 Limit Break, Final Heaven, using the Final Heaven item that you can obtain in Nibelheim.
Check out the Learning New Limit Breaks section for more information on how to teach your characters their strongest Limit Breaks.