Game:Terra-Xehanort

Xehanort appears as a boss in Terra's storyline in Keyblade Graveyard. He is also the final boss for Aqua in Radiant Garden during the Last Episode.

As Terra/The Lingering Sentiment
For Terra's final battle, first of all note that you are playing as the Lingering Sentiment rather than Terra in his normal incarnation. This means two things. First, you will no longer be able to Dimension Link. Second, Lingering Sentiment is forced to equip Gaia Bane as it's Keyblade, so if Terra was using a more powerful weapon such as the Delicious Tower before hand be prepared for a slight drop in offensive power. Otherwise you will retain the Command Deck you had set up on Terra before hand including all Commands, Shoot Locks, and Items. You can still enter Terra's Command Styles here, however maintaining them is difficult so they might not see much use.

A good Command set up is one Curaga Spell preferably with an added Leaf Bracer ability, several attacks that hit multiple times such as Chaos Rave, Solo Arcanum or Sonic Blade and a powerful Shoot Lock. You will be guarding often so equipping Restore Guard or Focus Guard to recover HP or Focus Gauge is also advisable.

Xehanort uses Terra's moves or variations of such against you. Since Terra is the player character this makes it easy to predict and counter him, however this also means he can do two things most bosses can't. First off Xehanort can guard and counter as Terra would, so attacking him from behind is preferable, and also Xehanort can cast Curaga on himself making him one of the rare bosses that can heal. His healing cannot be interrupted however he can't or won't use it often so it should be easy to out damage his healing.

In the early stages of the battle Xehanort will use Terra's Black Volley Shoot Lock at you. He can fire it in the same homing pattern Terra can or he can fire it faster and straight ahead. Both of these can be reflected back at him by guarding for decent damage making it a good way to damage and open up a chance to attack. In addition he will use a multi hit combo attack that can be guarded and countered, and he will use Terra's Dark Impulse Command Style in both its regular combo finishing with a dark punch of energy (which can break through your guard so dodging is advisable) and it's finishing attack where Xehanort will dive under ground and attack you directly from below (to avoid wait until he's right under you and then quickly dash). Finally Xehanort will cast the Quake spell causing the earth to erupt around you. For movement, Xehanort can dash like Terra can and he can also teleport around the area.

Once he's significantly damaged he'll use a variation of the Meteor spell that will call down several meteors at once. You can avoid this by either dashing out of the way of all of them or moving to a corner and blocking them as best you can. After this the fight will continue as before however Xehanort will add two new skills to the mix. He'll cast the regular Meteor spell, and he'll use Terra's strongest Shoot Lock Ultima Cannon although he fires a single large ball of energy similar to the Lingering Sentiment battle in Kingdom Hearts II Final Mix rather than Terra's version. This can't be hit back at Xehanort here so dash far away from it when you can.

Xehanort has several powerful attacks but if you carefully guard and counter when you can, take advantage of Restore/Focus Guard for healing purposes, and keep hitting him with attacks and Shoot Locks when he's vulnerable, Lingering Sentiment will prevail.

As Aqua
In the Last Episode, Xehanort is basically the same as in the fight with the Lingering Sentiment.

However, once he summons his Guardian Heartless, the fight becomes much easier. Basically, the Guardian will throw all sorts of spells at you, which are easily avoidable. You must mostly avoid being hit by the Guardian's dark balls, which will render Aqua temporarily blind and leave her vulnerable to further attacks. Occasionally, the Guardian will dive underneath the ground and follow Aqua from below, shooting upwards every few seconds. Be sure to dodge the Guardian by using Dodge Roll, otherwise you will be caught and become victim to a deadly attack. Another attack will transport Aqua and the Guardian into Xehanort's mind, portrayed as a yellow abyss with Terra in the centre. To escape, you must fight your way past the Guardian and reach Terra. Hitting him will transport you back to the arena, but performing a specific action with Terra, if you're lucky, will end the battle there and then. Every once in a while, Xehanort will separate from the Guardian and unleash his basic combo on you, which can be easily guarded and countered just like in Terra's story.

Once damaged enough, the Guardian will no longer dive underground, but will separate from Xehanort and lunge towards you. If you are too far away, it will give up and return to Xehanort. At this stage, avoid attacking Xehanort directly and rely more on Shoot Locks. Throughout the entire second battle, be sure to use the correct Shoot Lock, since Xehanort will easily avoid Shoot Locks like the Rainbow Shower (unless you perform the attack while the Guardian is preparing to dive underground). Photon Charge, Absolute Zero and Lighting Ray are the recommended Shoot Locks for this battle. Stick to these rules and Xehanort will fall once again (and thus the game will end).

Video
Video:Kingdom Hearts Birth by Sleep Xehanort Boss Video:Kingdom Hearts Birth By Sleep Aqua's Final Boss Fight