The Inves are strange monsters that are thought to only exist within the newly popular Inves Games, which involves Lockseeds. They are eventually revealed to be actual monstrous animals that can travel to and from an alternate dimension known as the Helheim Forest to wreak havoc on Zawame. The standard variant of Inves is known as a Elementary Inves, a form humans are familiar with as the forms the Inves take while in a Inves Game.
However, the Inves can also take on a Berserker State, and only a Kamen Rider has the power to put a Inves in a Berserker State down. An Inves's Berserker state is triggered by eating a mature Lockseed.
When the Inves in its Berserker State consumes another mature Lockseed, be it the one that summoned them or a completely different Lockseed, such as when the Shika Inves ate Gaim's Ichigo Lockseed, they will evolve into higher form called Evolved State. If an Elementary Inves consumes a multitude of Lockseeds, than it is capable of bypassing Berserker State and evolve straight into its Evolved State.
The Inves reveal to have a virus. When attacking, the victims will have the plants from Helheim come out from the victims' body, as well most likely turned into an Inves. The Inves also seem to know and are able to control the virus, such as when the Inves first started to attack people no one was affected. However, the Inves only seem to affect people and inanimate objects when they are in need of immature Lockseeds to feed on.
There are also Inves created from humans that ate the mysterious fruits and are labeled by the Yggdrasill Corporation as Category H Inves. Yggdrasill considers such Inves to be nothing more than corpses animated and controlled by the forest's instinct. For some reason, these Category H Inves do not infect people with the pathogen that causes Helheim's fruits to grow from their wounds.
The ordinary Inves are ruled by an Overlord Inves, highly intelligent Inves that are far superior than humans and are the masterminds behind the outbreak and rulers of the Helheim Forest. Unlike an ordinary Inves, the Overlord Inves retain a human-like level of intellect, allowing them to speak, albeit in a strange language.
- Green Elementary Inves
- Blue Elementary Inves
- Red Elementary Inves
- Komori Inves
- Inoshishi Inves
- Evolved Inoshishi Inves
- Lion Inves
- Armored Evolution Lion Inves
- Yagi Inves
- The Elementary Inves are similar in henchmen-status and shape to the Salis Worms from Kamen Rider Kabuto and to a lesser extent, the White Yummy from Kamen Rider OOO, in that all of them are able to evolve into more powerful forms that take on the Monster of the Week position.
- The Inves are similar to the Mirror Monsters from Kamen Rider Ryuki in that they are more animal-life compared to the usually human-level intelligent kaijin in the Kamen Rider Series and are summoned by characters to face off against each other as well as taking a backseat to the conflicts between the Kamen Riders of their shows. In the case of the Inves, their status as monster of the week is even further subverted.
- There are three different types of Inves that feature Chinese (Green), Japanese (Blue), and Western (Red) designs. Each type of Inves design also comes from a different designer.
- Chinese (Green): Akihiro Yamada
- Japanese (Blue): Tamotsu Shinohara
- Western (Red): Niθ
- Coincidentally, the three types if Inves (mostly the Overlord) match up with three of the four main Rider's color scheme and warrior theme: Gaim (Blue, Japanese), Ryugen (Green, Chinese), and Baron (Red, Western).
- These also seem to be the types of Inves in each of their respective armies in the Sengoku Rider War.
- Coincidentally, Rosyuo, the white Overlord King, also match Zangetsu or Zangetsu Shin's color scheme.
- The name Inves comes from an abbreviation of the term "Invasive Species".
- The Green Inves all resemble jade statues.
Evil Army Shadow Line
Shadow Monsters: Bag Shadow | Saber Shadow | Chain Shadow | Stove Shadow | Bucket Shadow | Seal Shadow | Bomb Shadow | Marionette Shadow | Type Shadow | Lamp Shadow | Loupe Shadow | Vacuum Shadow | Hammer Shadow | Ring Shadow | Fence Shadow | Jack-in-the-box Shadow | Soap Shadow | Hound Shadow | Pin Spot Shadow | Coin Shadow | Bottle Shadow | Wig Shadow | Table Shadow | Chair Shadow | Syringe Shadow | Billiard Shadow | Clock Shadow | Fountain Pen Shadow | Film Shadow | Tombstone Shadow | Dollhouse Shadow | Tank Top Shadow | Behemoth of Darkness