Kingdom Hearts: Chain of Memories/Sora/Hollow Bastion

Upon Sora's, Donald's, and Goofy's arrival, Belle and Beast are having a conversation. Belle, acting strange, tells Beast that she's going to stay with Maleficent. She leaves Beast, and the three offer their help to Beast, who leaves shortly after. You'll get the Key of Beginnings after the cutscene finishes. These Heartless require you to be at high levels, especially the Defender, the toughest Heartless in the game. Either run past all of them or try to fight if you think you're leveled up high enough. Take the door to the west and synthesize using a card with a value of 1 or higher. When you get to Room 2, once again, you have two options: kill all of the Heartless or run and avoid the battles. Take the door to the west and do the same as you did in Room 1, synthesize using a card with a value of 1 or more. Strike the door to the east and use a Moogle Card if you have one. If not, go back to Room 3 and head to the door at the west of the room. Use a card with a value of 6 or higher to get through the door. In Room 4, head to the door at the south of the room and synthesize using a card with a value of 7 or more. In Room 5, kill all of the Heartless and strike the door. Synthesize with the Key of Beginnings, a Magic Card, and a card with a value of 3 or less. You'll reach Room 6, where you'll see a cutscene. The three meet Belle and afterward, see her and Maleficent have a conversation. Maleficent leaves and takes Belle with her. You'll get the Key of Guidance.

Go back out the way you came and you'll be in Room 4. Synthesize using a card with a green border, a card with a value of 7 or more, and the Key of Guidance. The next room will have another cutscene. Maleficent is trying to make Belle call Beast over and fall for the trap. Sora, Donald, and Goofy intervene, and Beast arrives not long after. Belle tells him to leave because she doesn't want to see him so he won't get hurt by Maleficent. Beast, unfortunately, is hurt emotionally by her words but decides to stand his ground. After he explains why he looks the way he does, Maleficent announces that Beast's heart is purer than Belle's, and decides she's going to take his instead. Belle, however, jumps in front of Beast and takes the attack instead, transforming into a heart which enters Maleficent's scepter. Maleficent leaves and Sora, Donald, and Goofy once again offer to help Beast. You get the Key to Truth after the cutscene. Go back to Room 3. Head to the door to the east of the room, then head to the north door in this room, and then strike the left door in this room. Synthesize using an Attack Card, a Gimmick Card, and the Key to Truth. After the next cutscene in which Maleficent transforms into a dragon, it'll be boss battle time.

Maleficent
Maleficent won't be too hard of a boss as long as you're at the right level (which is probably at least 37). Use the usual attacks and combos and avoid her attacks and combos by card breaking or dodge rolling. Thunder, in this case, is a good card to use. It doesn't require getting close and can easily hit the large dragon. Her health reaches a third health bar, but this isn't too big a deal. It isn't as hard as it is time-consuming, which, even then, shouldn't take too much time. Maleficent's attacks include: After the next cutscene in which Belle returns, leave Hollow Bastion by climbing the ladder in the next room.
 * Maleficent stomps on the ground to create a shock wave that stretches pretty far. Jump over this one, as dodge rolling would have obvious consequences.
 * Maleficent lunges at you with her head, trying to get a good bite in. Dodge roll this one and it should be easily avoidable once you're in a far range.
 * Maleficent spits fire, which spreads across the ground and can prove quite deadly and hard to avoid. When you see her preparing this one and don't have a chance to card break, get away.