Time Stone

The Time Stone From WWL 2:Battle Between Brothers was used to seal Mario in the Overforce and used to travel back in time.

Backstory
Baby Mario found a rare stone used to travel in time.He used in to power his time machine which was never used since the episode is non-canon but used in the movie. In an unseen prequel story, Captain Toad is the one to discover the Time Stone during an expedition in his youth.

Appearances
The Time Stone was shown being used first in WWL 2 When Waluigi Found it and used it to stop Mario but unexpectedly it sealed him in The Overforce instead

The Time Stone was also used for The Overforce to travel back in time to Season 1 Of Baby Luigi VS The Overforce. So, Wario also used it to travel back in time when some of the evil spirit of the Overforce went into Baby Mario And figured out why the Government chose Baby Mario Instead of Luigi.

The Time Stone was revealed to be used again in season 4 of Baby Luigi VS The Overforce

In Overforce Uprising, the Time Stone is used by Captain Toad to time travel through dimensions due to the weak fabric of reality.

The Time Stone was found by the Government in Oververse and it was used as a weapon.

Uses
The Time Stone is used to travel back in time for 5 minutes then back to the present. It has been shown to travel into other Universes. The Time Stone Also Sealed Baby Mario in The Overforce then he traveled back in time but left The Stone behind.

After it's use in WWL 2, it damaged the fabric of all the universes due to the raw way Wario used it. This would cause the Oververse arc to begin along with many important events that would shape the rest of the movies and TV shows to come.

Universal Collision
Following the events of WWL 2, the Time Stone used without being stabilized ruptured all the universes, causing them to eventually collide. Before the portals started appearing it caused many effects prior to the collision. One of which being the darkness spreading from Diddy Kong's time machine since the fabric of space and time was being torn apart, it was the first to be affected. The darkness would also lead to many tragedies to happen in Old Universe 2.

Weaponized Time Stone
In Oververse, the Government retrieved the Time Stone and was able to use it to make himself extremely powerful and almost unstoppable. This would be the last time the Time Stone makes an appearance