Game:Lingering Will

The Lingering Will is an unlockable secret boss featured in Kingdom Hearts II Final Mix. His boss battle is unlocked when the player unlocks The Gathering, then returns to Disney Castle's Hall of the Cornerstone, where a portal to the Keyblade Graveyard has appeared. Defeating the Lingering Will grants the player the Connection Proof, and the Lingering Will can be refought by leaving the Keyblade Graveyard and then returning.

Strategy
Sora mostly needs to dodge the Will's attacks by using Dodge Roll or Guard, specifically for when it swings his Keyblade around or turns into Terra's Keyblade Glider. Sora's attacks will deal an insignificant amount of damage and the only ways to stop this effect is to land a combo on it or having the Ultima Cannon's bomb deflected back at the Will, and the damage it takes will be normal. It will mostly use the whip technique after it has been hurt badly a few times, particularly by a powerful finishing move, so use Quick Run to avoid this after striking him hard twice. If it transforms into the floating guns, just deactivate Lock-On and fly as far away as possible, and turn around stone pillars to make the guns destroy themselves. For the cannon, just deflect the bomb back at it using Guard, and if it isn't possible, just Dodge Roll through it (it will explode without hurting Sora, but be careful with Donald and Goofy). Once it goes into the berserk state, Guard as much as possible and when it strikes the ground, fly for it. Once it gets ready to strike again, cast Reflect as much as possible until its attack finishes, where Sora should strike it with Thundaga to leave the Will vulnerable to a good retaliation.

Make sure to load Sora, Donald and Goofy with Ethers in case the Will casts the spell on Sora which stops him from using Magic. Be extremely careful when it gets ready to transform its Keyblade into a Bow to trap Sora in a energy-draining triangle when shot, replacing his commands with "Fall" (which will do extra damage for each input), and "Escape", which will make the trap disappear (the Escape command appears in the command list in a shuffling manner and requires good timing, while avoiding any situation that may lead to too much damage/instant death). A good indication is when his Keyblade makes a gun-loading noise. As soon as it's heard, get ready to Dodge Roll at a specific timing rate or repeatedly use Reflect to prevent the beam from hitting. At the start of the battle, it will shoot three times (but later four times). If the shot is successful the Will always attacks with an Ultima Cannon, so Sora can retreat and wait for the shuffling to slow down. Then press escape and avoid the Ultima Cannon by using Quick Roll or Dodge Roll on it. When this happens the Will tends to use its energy drill combo. If one is successful after blocking the last shot, strike the Lingering Will hard.

At times, the Will will start running towards Sora. If he is too far away, it will jump towards him and maybe land near Sora, giving him a striking chance. If the Will is running near him, it will either use a basic but powerful Keyblade move that ends in a drill of energy, (similar to Sora's Guard Break) or it will throw his Keyblade into the ground and create a vortex of energy. If this attack hits Sora, it will take away his ability to either attack or use magic. A small lifebar will appear for the Will and Sora will have to drain this in order to regain the lost ability. The best magic to use is either Fire or Thunder, but be sure to equip only one of these with Reflect and Cure. If Sora can't use magic, be extremely careful, as he will not be able to heal himself. To avoid the drill, just stay in the air above the Will and hit it once it puts it away. In the case of the vortex, be sure to observe the Will and either use Dodge Roll or Reflect at the precise moment and Sora will escape. The Will is still invulnerable during this time.

Watch out for lethal combinations such as the boss trapping Sora in the triangle, going into the berserk state while he can't Attack or use Magic; or if it summons two guns to aid itself while it flies around on his Keyblade Glider. If Sora has Once More and Second Chance equipped and gets hit by one of these combinations, just let the Will keep hitting Sora while he's in the air and the last bit of energy will stay with him. Once it's over, one should heal if they can.

It should be noted that the Will has a tendency to repeat its attacks for a couple of rounds. That is to say that if it uses its air thrust attack, it is expected for him to repeat this attack for a while, unless a considerable amount of time has passed or he takes a lot of damage. When this happens one should pay attention as its "attack of choice" becomes more aggressive as its HP falls, often repeating the attack several times before being susceptible to damage, or unleashing a whip attack at the end of the combo. In the case of the Slider this can become fairly frustrating as it can often unleash to light guns, making it difficult to avoid and find room to attack although using Reflect can help with the guns somewhat. It can also attack with chunks of ice as it dashes, which can be fatal since the Blizzard magic is considered a separate attack so even with Second Chance or Once More, the combination of both cause Sora to fall. A way to defeat the Will is to fight with it and get used to the timing and methods of its attacks as it repeats them, which will considerably reduce the difficulty of the first part of the battle.

The second phase of the battle (when it goes berserk) is always signaled by two things: 1) When its HP is slightly less than 7 bars and 2) it will always turn itself into several guns of light that will dispel as soon as it goes berserk. The second phase of the battle can be difficult, as its berserk attack can last for quite a while and failure to block or evade the entire attack can result in missing an attack opportunity, which during this phase can be fatal. This is because the Will becomes completely unpredictable and can unleash any of its attacks in rapid succession leaving almost no room for offensive or sometimes healing. This is made worse as the Will uses its command lock attacks such as the vortex or his bow attack much more often. However, there is a catch during this phase to bypass this entirely. If the Will is attacked right after its berserk combo, then it will repeat the berserk combo again and maintain this pattern for the remainder of the battle each time it is hit after its combo. If Sora fails to evade or block the entire attack an extremely easy way to ensure the Will is hit is to cast Thunder magic as soon as the combo ends. This will launch the Will into the air giving Sora time to either heal or attack the Will with a combo of his own. This prevents the Will from defeating Sora with an unpredictable amount of attacks, since the only requirement to keep him locked into repeating his berserk combo is to hit him after the combo ends. Repeat this strategy and even this phase of the battle can become relatively easy to conquer.

Despite being one of the weakest, the recommended Keyblade is the Kingdom Key (given Sora is at level 99), because it gives the Damage Control ability. One can use Fenrir or Rumbling Rose, but Fenrir has the disadvantage of Negative Combo and Rumbling Rose has the Finishing Plus, which will make the Will angry quite quickly and force it to use the whip attack when Sora is not ready to guard. Oblivion would be quite useful as well, but as the Kingdom Key is weaker, it will take the Will more time to get angry. At first, striking it takes little health away, but the longer the combo is the more health the Will will lose and the more powerful the finishing move will be. The Ultima Weapon is also a viable option if Sora uses a lot of magic to either defend himself or to stun the Will with Thunder.

In times of desperation, Sora can quickly use Limit Form to regenerate health and MP if he is almost out of both and Donald and Goofy are out cold. Be careful to do it so the right place, as the Will may unleash an attack that will hurt Sora immediately after he transforms, or he might be sent into AntiForm. To make sure Sora doesn't go into AntiForm, go into Final Form at the start of the battle and immediately revert back once Sora has the chance. It wastes Drive bars, but it's a 100% guarantee that Sora won't go into AntiForm when trying Limit Form. Do not try to use any special Limit Form moves on the Will, as they will do it little damage. Try to heal close to close to Donald and Goofy, so they can use their Ethers on Sora.