Angel Wing is Rinoa's own form of Sorcery. You will automatically obtain this Limit Break at a certain point in the game. Since she has yet to learn how to control her power, Angel Wing is actually a status where you lose control over Rinoa during the battle.
Angel Wing Status
During this status all of Rinoa's stats, especially Magic, are boosted. It's even possible for stats go beyond the maximum number: 255. It's best to boost her Magic and Speed stats to maximize the possible damage dealt while on this status.
On each turn, Rinoa will cast a random enemy targeting magic spell on a random enemy. She can cast elemental magics, status weakening magics and ancient magics. The CPU also seems to prefer casting combos, such as Meltdown followed by Meteor.
If Rinoa is in a bad status, starting Angel Wing may fix it! These statuses include Mute, Poison, Slow, Blind, Doom and Petrify.
Angel Wing Summary
Angel Wing is like Berserk Magic. It ends when Rinoa is KO'ed, Petrified or the battle ends. If Rinoa is on Invincible status or locked on certain statuses, Angel Wing status can actually "miss" when you attempt to use it!
Magic used is random and normally varies between what Rinoa has junctioned. She will not heal, revive or aid status of other characters. Always Junction the best offensive magics that you have and avoid Scan completely.
Offensive Magic used is 5 times stronger than normal for Rinoa's current stats.
Each spell casted does not use any of Rinoa's stocked Magic.
Silence, Berserk and Confuse, statuses are nullified. Rinoa can get hit by Stop, Sleep, Float, Blind, Slow, Zombie, Break, Pain (will not be Silenced) and Bio but will continue to be in Angel Wing status.
When no Magic is junctioned, Rinoa does normal attacks as though Berserk.