A few questions to help balance Vegeta during this and maybe nerf him as needed:
- In regards to the demon realm, is the decay in energy similar to all of those in there, or will it hit others stronger?
- Would having a higher energy output cause it to effect a person stronger? (aka, Vegeta in Blue form getting hit harder by the energy drain than super saiyan or base form)
- Would ki sensers be able to sense the demons strength and locations?
- Is demon flesh able to be consumed safely (if not by humans than maybe saiyans) or is it complete toxic to all life forms?
- I spotted someone saying this is Doom related, is this a good scale to judge enemy strengths by?
- Does the keystones have any resilience to attack or is it just the guards supposed to be protecting them?
- What would be suitable flight times between the city and the portals, and the keystones within the demon realm itself, keeping in mind Vegeta is capable of incredibly high speeds?

I just don't want Vegeta to be too op within this, so any suggestions to help make him struggle will be helpful. I am hoping the drain on energy will be a good one to use on him, because I am sure now he has space to let loose he will go into Blue form for as much as he can to make the most of the time on the stop.

Thank you! :)

Edit: Quick edit as another thought if above doesn't nerf him then an idea/suggestion: Is it possible for him to get bored enough to go searching out in the demon realm for something stronger hidden within it? More than understandable if not, depending on what you have planned for the event and other stages of it, as don't want to wake up something too big and bad too early or at all.