It's alright I did suggest that in the EU4 segment of his next mega campaign he does little to no colonization at all, but I do understand that it's going down a simmilar path to that of the Annionas so he should try going after Persia and the Knights of Santiago and leave Asia alone for some time.Personally, while Japanese Emperor Norton is fun, I feel we've been down this path before. We have the Ming exploding again, your dynasty conquering land in Asia, conquests and vassalizations everywhere, and putting your dynasty on other countries through marriage and conquest. I'm wondering, how can you make sure this doesn't become a rehash of the Annionas and their expansion in your previous megacampaign?
Also, Japan conquering China would be really immersion-breaking. A colonial China exploding in a similar way as real life is already bad enough. There's no way Japan can take over all of China and keep it, in any time period.
I'm sorry for the rant, I just needed to vent a little.