The summary for the Kamen Rider Wizard In Magic Land movie has surfaced online recently. In short, spoiler alert! Read at your own risk!
At the start Sorcerer is standing at the top of the building, for some reason Koyomi is lying down unconsciously beside him, then Haruto appears, transforms, and the battle starts. Then Socerer uses the Create Ring and sends all of them to the Magic Land.
Rinko and Shunpei are also in the Magic Land, but they don't recognize Haruto. A bunch of Ghouls appear, and Rinko, Shunpei, Doughnut Shop people etc transform in Mage to fight them. All the people can use magic here and can transform. Rinko takes Haruto and Koyomi to meet the Emperor Maya. Haruto mentions to Rinko about the Golden Wizard, Rinko replies that they do know the existence of the Golden Wizard, but to Haruto's surprise she was actually referring to Kousuke Nitoh as Beast.
A little boy called Shiina works in the Antique Shop for Wajima. He is a gate who is pursued by Phoenix, Medusa and Gremlin. Haruto is on his way to fight the Phantoms and he sees Kousuke fishing for mayonnaise, so he takes him to battle as well. Wizard transforms into Flame Dragon, uses his Drago Timer and summons the 4 forms, Beast upgrades to Hyper and finishes off Medusa, Water Dragon and Land Dragon kills Gremlin whilst the remaining two kills Phoenix. Then both of them enter Shiina's Underworld and destroys his not one, but two dragon Phantoms.
Sorcerer goes around and kidnaps people at night time, and Shiina's mother died because of this, the dead ones are all put onto the machine and the bones are on top of each other. Haruto and Kousuke uses the Small Ring and flies into the castle on a bird, then uses Dress Up Ring to get the uniform sorted. The two unfortunately were spotted by Maya and had to escape, they meet Orma (Sorcerer) on the way. Beast said that because it's their homeland he wants to sort it out on his own and lets Wizard escape first. Sorcerer's power was enough to kill Beast but Beast escaped thanks to the Chameleon Ring.
Maya tells the whole Magic Land that Haruto was an intruder, the Mages appear and starts attacking Haruto. Because it is the Magic Land magic is used as a currency to pay for everyday items, but this was also a major conspiracy. Haruto starts to destroy these paying devices around town and this created more tension between the two sides. Koyomi comes out and says she believes Haruto no matter what, Shiina does the same and so do Rinko and Shunpei. Beast finishes off the Mages and Haruto goes into the castle again.
At this time Maya activates the device, everyone who had magical powers started to fall into despair, the only people who were immune to this were Koyomi (human shell), Shiina (inner Phantom destroyed) and Maya. Yes Maya actually does not posses any mana at all.
Sorcerer appears and reveals that he is a Phantom. Haruto finds his hope from despair and transforms to Wizard. He then starts using all of his Styles and ends it with Infinity. Wizard takes out the Finish Strike Ring, turns into Infinity Dragon and defeats Sorcerer. Sadly, the origins of the new Ring was not revealed in the movie.
Haruto and Koyomi returns to the original world. Haruto then checks if Shunpei for any belt, and then checks out Rinko only to get slapped by her.
Source: KamenRiderUNDERGROUND of HJU