A time stone is an object that creates a portal that allows somebody to go in time. Mickey and
How It Works
Somebody has to use the time stone, and it'll create a portal that can allow somebody to travel through time. However, if somebody uses a time stone, it's power will run out and it'll be useless.
A time stone looks like a regular, purple mineral. However, when it has no more power, it turns grey.
The Blue Terror
Time stones first appear in the Blue Terror, though nobody calls it a time stone yet. It all starts when Mario and Luigi watch the news. The news people talk about portals in the forest. News person #1 says that he thinks the portals lead to another dimension and News person #2 think that they lead to another planet. They have a big fight over it, but in the end, News person #1 defeats News person #2.
After Gonzo retreated from Mario and Luigi, he sadly walks toward the forest. In the forest, he finds some black liquid, which was probably a crushed time stone. He moves it with a stick, then he touches it curiously. Some black comes and it is unknown what happens to Gonzo, although the power of space and time gave him electrical powers probably.
Mario and Luigi watch the news again, which is somebody (probably John MChansen) under an umbrella talking about portals. He then sees something, then he screams and the video camera gets knocked down. Mario and Luigi go to check it out.
When Mario and Luigi were looking in the forest, Luigi fell from a log, but his hat kept him on the edge of the log. Mario made some cushion under where Luigi was going to fall. When he was done, he told Luigi that he could fall. When Luigi fell, he got dazed and started crying, even though he fell on all of the cushioning. They decided to see if there was something under it, and there was a time stone under it. Luigi decided to touch it, and when he did, it made a portal. Luigi decided to go in it, and Mario went after him.
Mario and Luigi went to their past, which was the first level in game Super Mario Bros. (actually was Super Mario Bros. Deluxe), but Luigi kept dying. It took him many hours, but he completed it. Mario completed in one try.
Meanwhile, Gonzo travels to the past too. He travels to the time of Find Yoshi!. He tries to steal Yoshi, and in the end, he trained Yoshi to be his bad guy pet. However, in the end, Yoshi betrays and defeats Gonzo. Thus, Mario, Luigi, and Gonzo were transported back to the present. The rest of the movie doesn't mention portals.
The Rise of Gonzo
In the the Rise of Gonzo, Mickey tells Mario that he has to fix his relationship with Luigi, who turned into Cool Luigi in Mario's Rock Band. Mario refuses, so Mickey uses his last time stone to show Mario what the future would be like 100 years later if he didn't fix his relationship with Luigi.
When Mario was ready to go to the past, Mickey said that he used his last time stone to create the portal earlier, so Mario would have to go on without him.
- The time stone can be used by multiple people but can only be used once, and the time string can be used by only one person, but you can use it as many times as you want.