So Niche really is like a demon (or dragon more appropriately) in human form. Interesting.

I had thought Lag could see the memories of other Shindan bullets because of the amber in his eye. Is it the case that anyone can see them, or is Niche special on that front as well? She saw a quick summary of most of who Lag cares about, notably which included herself.

I don't see it as a shonen power up ability. He's really weak otherwise, which is why he needs such a powerful dingo. It's basically the only thing Lag can do. He can't even defend himself against normal snakes, but he's the only one who can completely defeat a gaichu.