Aeris' Princess Guard: In the Temple of the Ancients, enter clock hall IIII. Look inside the chest.
Aeris's Great Gospel: Restores all heroes' hit points and magic points and makes everyone invulnerable for a short time. Visit the sleeping man in a cave southeast of Midgar. When you have fought more than 600 battles and the last two digits of the number of battles you've fought are the same (88, 177, 2344, etc.), he will give you a piece of Mythril metal. Take this to the blacksmith near the Gold Saucer, and open the smaller of the two chests to find the limit break.
