I'm guessing the monster that they're fighting is this universe's equivalent to Zelganoid, the corrupted man-made Ultraman from the 3-part finale of Ultraman Dyna?
I'm surprised the author didn't put Transformers in here.
It's originally a US/JP crossproduction based on licensed Japanese toys, so it'd be a little out of place with these series that were fully American made (unless they were to use something like the live action movies for a piece like this).
Fun fact: The human liver can regrow if anywhere up to 90% of it has been removed. The reason we can still die of liver diseases is because it can be damaged beyond its capability to repair itself.
