Super Peach's Castle of Fury
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Super Peach Castle is a boss in the game Mario & Luigi: Bowser's Inside Story. It is a portion of Peach's Castle modified to transform into a giant robot. Bowser must become giant to fight it.
When Bowser follows the incomplete Dark Bowser out into the castle grounds, Dark Fawful arrives in front of Bowser, who gets annoyed. Dark Fawful then mentions how he needs more power. He also replies that Bowser's meddling has given him fury as large as the world, then taunts Bowser while saying "SUPER PEACH'S CASTLE OF FURY!". This causes part of the castle to transform into a giant mecha which crushes Bowser under its foot. After Mario, Luigi and Starlow go to the Rump Command and supercharge Bowser's adrenaline, the Koopa King becomes giant again, throwing the castle off of him and beginning a battle.
Battle
Phase 1
Super Peach's Castle begins by firing a dark orb that forms a black hole behind Bowser. Every turn, Bowser must beat the vacuuming force of the black hole as it tries to suck him in. The Castle attacks by charging at Bowser and trying to push him into the black hole-Bowser can counter by curling up and rolling forward (drawing the stylus in a circle), eventually pushing the mechanical menace backwards. The boss can also fire huge black missiles from its towers, which Bowser must punch out of the air. After a turn or two, the Castle deploys a swarm of Mechawfuls, which Bowser can remove with a blast of fire breath. If hit with sufficiently powerful flames, the Castle reacts by ejecting "all heated cargo", giving Bowser a Refreshroom. After Bowser deals enough damage to the castle, Phase 2 begins.
Phase 2
The castle will begin this phase by firing an unavoidable (but moderately damaging) laser beam, which will instantly knock Bowser into the black hole behind him. While in the black hole, Bowser takes constant damage, so the player must stroke right to escape the black hole and launch him towards Super Peach's Castle, dealing damage. (This strategy applies to whenever Bowser is knocked into the black hole, but this is the first mandatory instance of it).
Noting the success of its tactic, Super Peach's Castle tries to make a second black hole, only for Bowser to knock it off course with a fireball. The new black hole appears behind the Castle, which also raises a force field that prevents damage from Bowser's attacks. At this point, Bowser must try to knock Super Peach's Castle towards the second black hole with his punches. If knocked into the black hole, Super Peach's Castle will take some damage before launching itself towards Bowser-the Koopa King must punch the flying robot to avoid injury and deal some extra damage to the Castle in the process.
In this phase, the Castle adds new attacks to its repetoire. It can release spikes from its fists before charging at a curled-up Bowser; the player must slide the stylus up just before the robot gets in range to make Bowser jump to safety. The Fawfulized palace can also release a small swarm of Mechawfuls which hover in the air before charging at Bowser-the titanic turtle can shoot them down with two fireballs each, but must be careful not to miss, as he has limited ammunition and a short window of opportunity to prevent injury. Additionally, both combatants must be mindful of the black holes, which will occasionally try to drag them into their whirling grasp.
Phase 3
When its health bar drops below 50%, the Castle will bring the black holes closer to the two titans, decreasing the amount of effort needed for either combatant to be knocked in (luckily, the black holes stop trying to suck Bowser or the Castle towards them). If the Castle is sucked into a black hole, it will use the Boo System to become invisible as it launches itself toward Bowser; the King of the Koopas must time his punch to avoid damage and a near-certain trip into his own black hole. On the other hand, if Bowser is knocked into a singularity, the Castle will defend itself by raising and lowering its spiked fists. Bowser must time his escape to avoid running into the spikes, lest he simply bounce back into his whirling prison.
Super Peach's Castle loses its shield at this point, allowing Bowser to damage it with his punches again. It lacks any new attacks besides its black hole defenses, but it ups the intensity of its old ones. If Bowser has a Refreshshroom, he should use it before reducing the Castle's health below 10%-after that point, he won't get another chance.
Final Blows
As Super Peach's Castle's health drops to critical levels, both combatants will be sucked into their respective black holes, which promptly move even closer together than before. Taking constant damage once again, Bowser must repeatedly launch himself towards the Castle, timing his charges to avoid its spiked fists.
After a few more hits, Super Peach's Castle finally admits defeat and reverts to its building form, leaving Bowser free to hunt down Dark Fawful within its depths.
