Bowser

"Your journey ends here Mario Bros, as I'll be the one finishing both of you with my new powers!"

Bowser, also known as the King of the Koopas, is a boss character who appears in the Prismverse Saga. He'll appear a number of times as a main villain in the episodes, while in some, he'll play a minor role. Kenny James is his voice actor.

History
Bowser has been the nemesis of Mario Bros ever since their first adventure back in 1985's Super Mario Bros. He's been the main antagonist of many Mario games ever since, his main plot being to take over Mushroom Kingdom and make Princess Peach his queen. But his plans are always thwarted by Mario Bros, even if he has the upper hand at various occasions.

Bowser has also helped the heroes sometimes, whenever his domain is stripped by another villain or so. And has appeared in various spin-offs as well.

In Prismverse Saga
Bowser is one of the main antagonists in Prismverse Saga, as he appears in half of the episodes as the main villain. In others, he's either downed to a cameo, or even a supporting character to the heroes.

In SMATSP, he makes an alliance with a mysterious woman, and retrieve one of the Star Prisms for himself. Ever since he gets it, he tries to gain the full control of the powers within the artifact, as he enters a demonic new form in the process. During his fight against Mario Bros, he fully enters this new form and almost comes out on top, if it wasn't for Mario Bros who managed to gain full control of the other 6 Star Prisms they got. After his defeat, he is taken to safety, and plans their next move. He manages to ambush the Mario Bros. and get all 8 Star Prisms, but his ally turns on him, and uses them for herself. After this subtle betrayal, Bowser is gravely injured from an elemental blast came from her new form. But he manages to land the final blow on her, after Mario Bros. weaken her enough to give him a chance. In the credits, Bowser decides to make a truce with Mario Bros and Princess Peach, wanting some time for himself.

He returns as a cameo in ROTMK, who orders Koopa Bros to steal some of the treasures that Monty Moles are after, to show them a piece of his mind, but of course, his plan fails.

His future appearances afterwards are [REDACTED].

Boss Battle (SMATSP)
(WIP)

Trivia

 * The music that plays when Bowser talks in some cutscenes is Bowser's Theme from Mario & Luigi: Dream Team.
 * The music that plays during his battle's first phase is a remix of his battle theme from Super Mario Bros. 3, which was remixed in Super Smash Bros. Ultimate.
 * The music that plays during his battle's second phase is Arkham Battle 2 from Devil May Cry 3: Dante's Awakening.
 * Bowser's new form, Oni Bowser, is inspired from Dark Bowser from Mario & Luigi: Bowser's Inside Story and Lucifer from Ghosts N' Goblins.

Lore
Bowser is the recent King of the Koopas, taking up the place of his father; Bowsedgar the Daring. When he was a baby, as his father was busy with the warfare, he was taken care of by a Magikoopa named Kamek, and almost managed to separate two babies that were brothers, only to be stopped by the other baby and a Yoshi. After this, he was brought back to Dark Land, and his father took care of him.

In his youth, he was a vicious and merciless Koopa who trained in harsh conditions with the help of commanders under his father's lead, and was prepared for warfare from a young age. When he entered the throne after his father passed away, he was in his peak days.

He obtained a powerful artifact in his first year of ruling, which allowed him to turn the Toads into stone and he captured Princess Peach, after finding out that she can revert the curse. Two brave heroes thwarted his plans, and the curse was reverted. But he didn't give up. He had thought of various convoluted schemes, like invading the 7 main kingdoms of Mushroom World, almost taking over Dinosaur Land, and even stealing the Star Rod and becoming nigh-invincible. But all his plans were put an end to, by the same brave heroes who stopped his first scheme. No matter what he did, those two heroes were always after him.

But meeting a mysterious woman recently and making her an ally of his, would possibly change his fate. After getting one of the Star Prisms in his hands, which includes the powers of the seven deadly sins, maybe this was his chance: This was the time where Bowser would defeat his enemies for good. But before this fantasy, he needed to gain full control of this artifact, he knew he wasn't strong enough to use it at this state.