Bowser fell through the smoke & ended up in an unknown area where he was approached by a hooded figure. Many Days Later,Mario,Peach,Yoshi,& Donkey are invited to a competition. By the time they arrived,They met Link,Red,Kirby,Samus,Fox,Green,Captain Falcon,Ness,& Marth. They also encounter Bowser as well. Master Hand approaches and claims that a competition is a fighting tournament. He wants them to enter,but warns them that the Losers will get turn into trophies until the Winner is crowned champion.
They accept those challenges.

Round 1 begins:
Kirby vs Ness

Yoshi vs Red's Pikachu

Link vs Marth

Peach vs Samus

Bowser vs Donkey Kong

Captain Falcon vs Fox

Mario vs Green's Jigglypuff

Mario,Captain Falcon,Bowser,Samus,Marth,Yoshi,& Kirby made it to Second Round. Mario ask Master Hand about the Losers,which he explains that they'll be in the vault. Before the Second Round begins,Mario was advanced for the Semi-Final.

Round 2:

Bowser vs Marth

Captain Falcon vs Kirby

Samus vs Yoshi

After Marth,Kirby,& Yoshi loses,Samus suspects that there is something is going on in the match. Mario overheard Bowser talking to the figure. Before the Semi-Final begins,Master Hand appears and tells them to get ready.

The Semi-Final begins:

Mario vs Captain Falcon

Bowser vs Samus

Mario & Bowser defeated their opponents. Bowser reveals that the Trophies are Master Hands to keep except for the Princess he wanted if he wins. The Final begins with Mario & Bowser fighting eachother. Mario manage to overpower Bowser & throws him into the vault,breaking out the Trophies of the losers. After reviving them,The Hooded Figure appears,revealing to be none other than Ganondorf. He reveals that he had killed the Hero of Time before he was sealed away. He had broken free and sensed that the descendant is among Hyrule. Link states that his Great-Great Grandmother was only a kid taken as a slave before she escapes and starts a new life.

Master Hand transforms Bowser into Giga Bowser. They fought against him,but gets overpowered. Mario punches the box & the Smashball came out. He quickly catches and uses his Final Smash,sending Bowser & Ganondorf into space. The Heroes manage to defeat Master Hand. The Heroes thanked Eachother and head home. Mario,Peach,Yoshi,& Donkey Kong return to the Mushroom Castle where they find Luigi sleeping after hard work.

Mid-Credits:

Ganondorf & Bowser drifted in space in their Trophy forms where they were picked up by Crazy Hand and taken to see Master Hand,who survived the attack.