The second of the Trainbots has been revealed by Takara:
https://news.tfw2005.com/2022/01/06/takara-tomy-transformers-mpg-collection-masterpiece-trainbot-getsuei-images-447776
This follows Shouki, who was revealed last October.
It's hard for me to get excited about characters who were never featured in America. I bought a knockoff of Raiden once for ten bucks as a curiosity, and honestly the toys aren't that great. They're like a time capsule... a look at the original days of Takara robot design. They have a VERY "early Takara" aesthetic.
The new ones seem to be a mix of the cartoon designs and the original toys. Of coure, you'll be able to form Raiden once you have all six. I won't be collecting them, but the idea that Takara is branching out into combiners suggests that maybe they'll do Masterpiece versions of other super robot teams some day. Third party companies do an incredible job with them, so I can only assume Takara's efforts would easily rival them.
Zob (taking down the Christmas decorations today, which is always a thoroughly depressing chore)