Since both UA and the time between it and OV had a bunch of unseen events, and this is set in an alternate Earth exclusive to the series...
Argit should come to the school posing as a student, having stolen Kevin's ID mask - he wants to be paid off for a high-profile deal from the past and tries to find ways to corner Kevin in private areas of the school, but his failures and an actual overall confrontation will increase the comedic suspense of the episode.
As for Calvin S. Ixpointfive, how about we change his name to Calvin T. Wentytu (T. standing for Tellahase) instead, as it would make more sense since Calvin is supposed to be more powerful than Kevin. His middle nam and his surname is a reference to the number "22".
This is super clever, you guys! Sorry that I've been a bit busy with other things - I'm wrapping up the pilot to StreetM's Ben 10 reboot and I want to get through the intense seventh episode of HoE. In the meantime however, I'm aiming to make time for this masterpiece.
Wen and Calvin are just brilliant ideas, though I think we should call them "The Preposterous Pair" - preposterous means ridiculous and we can all agree that these negative copies of protagonists are lovably silly.
Also, you wanna give Jimmy Jones an elder brother or cousin who brings Ben's fan club to Soberfoes University? They'll have this oddly surreal cult and Gwen and Kevin will be the final two on their list - this episode should keep alternating perspectives to show the cult being nervous on how to ask Gwen and Kevin to join. They should keep preparing contraptions while Gwen and Kevin don't even know - the hilarious intensity will be perfect, and the final meet should be creative and odd.