Instructions
Collect the Byakko Badge, then head to the Protocol Ruins. Make sure the total level of your party is under 30, in other words, you can have one Digimon at level 29, two Digimon at levels 14+15, etc. Speak to the DRI Agent here and he will give you a Veemon.
Level up Veemon to level 5 in order to Digivolve him into a ExVeemon. This is the only Digivolution Veemon can make on its own without having another type of Digimon in the party to affect the greater Digivolutions.
Create the higher forms of Veemon with the following formula:
Paildramon - Veemon at level 20 and Stingmon at level 5.
Imperialdramon - Veemon at level 40 and Paildramon at level 50.
Imperialdramon Fighter Mode - Imperialdramon at level 99.
Imperialdramon Paladin Mode - Imperialdramon Fighter Mode and Omnimon at level 50.