Sora first encounters Leon in Traverse Town, after exploring the place and going into the Accessory Shop for the second time. Here, Leon's attacks are rather basic—he does a few occasional slashes and casts fireballs on Sora every now and then, but each attack deals substantial damage to Sora.
It is recommended that Sora train to level 9 and above; Scan and Guard may come in handy too—Guard should be used to fend off the fireball attack—deflecting fireballs will force Leon to lower his guard for a short time; but when used against Leon, he will immediately counterattack, rendering the Guard ability useless. Also, do not be shy about using the Keyblade: attack and block Leon's slashes while if possible. One advantage of this battle is that the entire First District acts as a battlefield, so if low on health, escape far out of Leon's reach and use a Potion.
One very useful strategy is to stay at a distance and wait for Leon to launch a fireball. Sora can attack to deflect it, dealing damage and stunning Leon. Sora can then hit him with a combo without fear of getting hit, then retreat and repeat the process.
The outcome of the battle is the same—win or lose—so one does not have to worry about being defeated. However, defeating him will result in Aerith giving Sora an Elixir as an extra from him early in the game.
Leon and Yuffie are fought in first seed of the Pegasus Cup, and Leon's abilities improve significantly here. Start by defeating Yuffie first, as she has less HP, and then concentrate on Leon.
This time, apart from the occasional slashes and fireballs, Leon goes into Limit Break mode when he has less than half of his HP left. This occurs when his Gunblade becomes longer and has a blue glow to it. This attack makes him more difficult to defeat; while Leon is in Limit Break mode, his attacks become more powerful. Simply use melee attacks on him while he is not in Limit Break mode, and as in the previous encounter, fend off the fireballs with Guard.
While he is in Limit Break mode, there are a few instances where he will walk slowly towards Sora and attack him. This is the cue for Sora to use Guard to fend off his attacks. When several Guards are performed successfully, Leon's Limit Break stops and he has to power up. This move may be time-consuming, but it does give Sora more experience every time he deflects Leon's attacks.
When Leon runs towards Sora and plunges the Gunblade into the ground, it is best to attack him from behind. Continue doing so until Leon's HP is depleted. As in the previous encounter, do not be shy about using the Keyblade, because Leon can now heal when his HP is running out. Remember to heal when necessary.
Leon uses the same strategy in the Hades Cup, except that instead of Yuffie, Leon's combat partner is Cloud. Here, it is advisable to defeat Leon first before concentrating on Cloud.
Kingdom Hearts Chain of Memories
Leon acts as a tutorial enemy, similar to the Unknown earlier on in the game. He teaches Sora the importance of card numbers and card breaking. He then goes on to tell Sora about sleights. After he is finished, he gives Sora the Simba card.
Kingdom Hearts II
Pain and Panic Cup
Leon and Yuffie are fought as the final bosses of the Pain and Panic Cup, as well as its Paradox counterpart, in the Underdrome.
Hades Paradox Cup
Leon is fought multiple times in the Hades Paradox Cup: once with Cloud, and once with Yuffie, Cloud, and Tifa as his allies.
Leon and Cloud appear as opponents in Round 40. Sora should be wielding the Ultima Weapon for this match. Since Sora has access to Drive Forms, make sure to use LVMAX Final Form and have a sub-Keyblade with high strength.
Repeatedly attack Cloud (since he's a greater threat than Leon) while in Final Form. Make sure to have both Form Boosts equipped, as well as Drive Boost and Damage Drive to stay in Final Form as long as possible.
Sora can also use Firaga repeatedly if both are near, but to max out damage, make certain Fire Boost is active.
Leon, Yuffie, Cloud, and Tifa are the bosses of Round 49. Sora should have Retaliating Slash for countering the bosses, Explosion and Aerial Finish for powerful finishers, Glide and Aerial Dodge at Level 3 to evade, Combination Boost for stronger Limits, Leaf Bracer for survival, Blizzard Boost and Thunder Boost for stronger Magic, MP Haste if Sora is willing to spam Curaga, and Second Chance, Once More, and Defender for higher defense.
Start by attacking Yuffie, since she can teleport and her attacks can affect a wide area. First, cast Thundaga, then Curaga. Glide away, then rinse and repeat. This is the strategy until both Yuffie and Cloud are defeated—Cloud should be attacked next because he is fast.
After they are defeated, choose to attack either Leon or Tifa. It doesn't matter which.
At this point, Reflega, Firaga, and Trinity Limit should be used. After one has been dealt with, heal with Curaga and then use Berserk Charge on the survivor until Sora lands the finisher.
Then, use Trinity Limit to land a few more hits and use up the rest of Sora's MP and resume Berserk Charge. Repeat this pattern until the battle ends.
Notes and references