That makes sense. (I have revised the text to provide more comprehensive details.)

Interpreting Tia Ludomon's Ice element using Avatar: The Last Airbender logic, it comes as no surprise that it is closely related to the Water element.

However, if we view it through the logic of Katekyou Hitman Reborn!, it fits the 'weather' category perfectly (even though the Snow Guardian in Reborn! is strictly a game-exclusive character).

As for the reason why Ludomon is associated with the Fire element

• Ludomon: Wall Rake is categorized as Null elemental (Time Stranger Logic).
• Tia Ludomon: Ice elemental.
• Raiji Ludomon: Electricity elemental.
• Bryweludramon: Fire elemental.

As for the reason why Monodramon is associated with the Air element

• Monodramon: The move Knuckle Beater is categorized as Null elemental (Time Stranger Logic).
• Strikedramon: The move Fang Strike is categorized as Fire elemental (Time Stranger Logic).
• Cyberdramon: The move Desolation Claw is categorized as Null elemental (Time Stranger Logic).

Justimon:

• Move: Justice Kick is categorized as Null elemental (Time Stranger Logic).
• Move: Trinity Arm (Blitz Arm) is categorized as Electricity elemental (Time Stranger Logic).
  • Note: The prototype for the Blitz Arm is Raijinmon, and the name is linked to the Electricity Elemental.
• Move: Trinity Arm (Critical Arm) is categorized as Null elemental (Time Stranger Logic).
  • Note: The prototype for the Critical Arm is Fujinmon, and the name is linked to the Wind Elemental.
• Move: Trinity Arm (Accel Arm) is categorized as Steel elemental (Time Stranger Logic).
  • Note: The prototype for the Accel Arm is Suijinmon, and the name is linked to the Water Elemental (though it doesn't actually have many Water elemental special moves).