Shiny RoboBowser

Shiny RoboBowser is an enhanced version of the real-world Bowser and the true final boss of Mario & Luigi: Paper Jam. It is a "giant" form of the regular Bowser, combined with the powers of Paper Bowser and his existing paper minions.

When Mario, Luigi, Paper Mario, and Starlow reach up to the real-world Bowser and Paper Bowser, they engage in battle, with the two Bowsers threatening to trap them in the mysterious book forever and burn it up. During this conversation, they also make mention that they had plenty of time to come up with a "plan."

This comes into fruition once Mario, Luigi, and Paper Mario battle the two for some time. The Bowsers tell them what they did was just a "warm-up" and proceed to come up with their ultimate plan. Paper Bowser fuses with all of his own paper minions into a sphere shape, which the real-world Bowser jumps into—forming together a gigantic real-world Bowser wearing cardboard armor of his own image (apparently formed from Paper Bowser and his minions).

As Shiny RoboBowser takes damage, his armor breaks, ultimately destroying his helmet and allowing Bowser himself to be targeted. However, he eventually reforms his armor throughout the battle as well by summoning more paper minions.

Eventually, upon Shiny RoboBowser's defeat, the form explodes and causes both the real-world Bowser and Paper Bowser to fall back down to the ground. Bowser flies out of his castle back down to the Mushroom Kingdom, while Paper Bowser attempts to grab the mysterious book again, but he gets trapped inside by Mario, Luigi, and Paper Mario.

Battle
One of Shiny RoboBowser's attacks involves clashing his fists a number of times before punching at the Mario Bros. After a few punches, he blows a stream of fire at Paper Mario, followed by a giant fireball that slowly goes across the screen. The player must jump as soon as the boss punches and shoots a stream of fire and then the fireball towards Paper Mario, or the player receives massive damage and is blown off the screen. The number of times Shiny RoboBowser clashes his fists is the number of times he will hit the Mario Bros. before unleashing the stream of fire towards Paper Mario.

Shiny RoboBowser's next attack involves him leaping offscreen and then landing on the targeted brother, squishing him. The player must hammer him back to avoid massive damage. The elliptical wind generated is a visual cue that helps the player figure out which target Shiny RoboBowser is landing on. If the player does not hammer at the right time, Shiny RoboBowser smashes one of the Mario Bros., dealing massive damage to the targeted brother and moderate damage to the rest of the party via a shockwave. Hammering him a few times stops the attack. If his armor is intact, Bowser turns his arms into wings and drop-kicks one of the Mario Bros. Pressing the character's button multiple times fends off the attack and damages him.

Shiny RoboBowser can also chase the Mario Bros. by using his paper wings. Paper Mario, as a paper airplane, should avoid the Fly Guys as Mario and Luigi jump over the incoming Goombas and Spiny Shells and should grab on to Paper Mario to avoid Bowser's fire breath. If the Fly Guys hit Paper Mario, he is removed for a few seconds, leaving the Mario Bros. exposed to Shiny RoboBowser's fire breath. After a while, Bowser homes in on Mario or Luigi. Jumping on his head deals massive damage to him.

Another one of Shiny RoboBowser's attacks turns his arms into massive cannons. He then jumps away and fires a barrage of projectiles; the purple crystal balls fired from his cannons are aimed at the Mario Bros. (the right cannon aimed towards Mario and the left cannon aimed towards Luigi), while the fireballs from his own mouth fly towards Paper Mario. Hammering back the projectiles at the boss damages him. If not, the player suffers major damage and random status effects: The crystal balls inflict Dizzy, and the fireballs can inflict Burn.

Shiny RoboBowser can also turn his arms into wheels and chase the trio down. As they run, Mario, Luigi, and Paper Mario must jump over Goombas and run underneath Fly Guys who will knock them back at the boss and eliminate them from the chase. Shiny RoboBowser also shoots fireballs at them, which has the same effect as the minions. At the end of the road, a Chain Chomp comes towards the playable characters, who must dodge it to trick it into hitting Shiny RoboBowser, knocking him over and ending the sequence in success. If any of the characters get hit by the Chain Chomp, it is prevented from crashing into Bowser, allowing him to speed up and hit any remaining characters at the end.

At any given moment when the armor's helmet is active, or whenever Paper Mario uses his Trio Attack Hammer on the same condition, Shiny RoboBowser unleashes his own version of Paper Mario's Trio Attacks, summoning a giant hammer to transform the trio into paper sheets while trapping them in a paper version of the arena. A unique cutscene plays only once when the player selects a Trio Attack in which Shiny RoboBowser will mock the heroes for thinking that their Trio Attack will work, before creating a Trio Attack Hammer of his own to smack Paper Mario's away. During this sequence, Shiny RoboBowser shoots a stream of fire towards any of the three playable characters, and the targeted character must jump to avoid the fire. If his eyes are looking up, Shiny RoboBowser does not breathe fire for a while before shooting at the targeted character, causing the player to lose timing. Jumping too early or jumping as a different character attracts the boss's attention, who releases the fire on them after they jump. If any character still remains after the fire attacks, Shiny RoboBowser gets frustrated and unleashes a body slam on all remaining characters. If all characters jump at the right moment, they avoid damage. Regardless of whether the Mario Bros. were able to dodge the attack or not, Starlow appears once it has finished to point out that Shiny RoboBowser's helmet flashed when he used his Trio Attack, and to inform the Mario Bros. to save their Trio Attacks until the helmet has been destroyed.

While the helmet of his armor is active, Shiny RoboBowser is considered a shiny paper enemy; as such, fire attacks deal critical damage to his armor. However, when his helmet is destroyed, he counts as a normal enemy, thereby taking normal damage from all attacks until his armor is regenerated.

During the fight, various shiny paper minions (e.g., Goombas, Koopa Troopas, and Shy Guys) occasionally enter the fight. While they do not actually attack, Shiny RoboBowser can absorb them at any time to repair his armor and recover health at around 25 HP per minion. These enemies do not give out Sparkle Cards as they are fought alongside the final boss. They do give healing items, however. If Bowser's armor is destroyed, all of the paper minions automatically flee.

Additionally, if his armor is destroyed, Bowser can absorb paper minions to restore his Shiny RoboBowser armor with 650 HP, or 476 HP when furious. If he becomes furious and decides to restore his armor at the same time, he restores the armor with 476 HP before visibly showing that he is furious.

Trivia

 * Shiny RoboBowser is the third final boss in the Mario & Luigi series to be a fusion of Bowser with another character (or, in this case, multiple characters).
 * Additionally, Shiny RoboBowser continues the series' trend of the final boss being a different form or derivative of Bowser, following Bowletta (Mario & Luigi: Superstar Saga), Shrowser (Mario & Luigi: Partners in Time), Dark Bowser (Mario & Luigi: Bowser's Inside Story), and Dreamy Bowser (Mario & Luigi: Dream Team).
 * Shiny RoboBowser is similar to the final boss of Yoshi's Safari, which was also Bowser wearing a suit of mechanized armor.
 * Shiny RoboBowser is the second enemy and first final boss in the Mario & Luigi series not to use 2D sprites like most characters, and is instead a 3D model, along with the Dark Block enemies from Mario & Luigi: Dream Team and Cackletta's spirit form from Mario & Luigi: Superstar Saga + Bowser's Minions.
 * Counting the armor's HP (as the armor is required to be destroyed to defeat the boss), Shiny RoboBowser has the highest total stats of all mandatory bosses in the Mario & Luigi series (not counting Chakron).

Bowser corazzato