Sage isn't programmed to be merciless though to the point that consciousness is questionable.
Sage was not only prgrammed to be an advance AI but succeeded her programming thanks to Cyber Space. But because she remained loyal to Dr. Eggman, instead of lobotomizing her programming, has taken more of a liking to her like a daughter.
Belle regarded Metal Sonic to potentially be a brother when in truth, Metal Sonic was designed to be a weapon, a weapon that Dr. Eggman dotes over but not overly sentimental with. Sage was designed to be an AI assistant that he has become sentimental over to the point of fatherly.
So, it would make sense for Belle to be somewhat jealous over Sage, if that'll be the case.
Yes, still Belle didn't know Sage at all for now, so she wouldn't know whether Sage is merciless or not, or what kind of closeness she has with Eggman.
That's why I think she could be caotious towards Sage at first.
Will be she be jealous or not that will come out a lot later.
Could this NDS scanner also be used for Dinosaur king and MushiKing cards? Or other games?
Yes for MushiKing, because SEGA's Card Reader supported three DS games:
1. Oshare Majo Love and Berry / Oshare Majo: Dress Up!
2. Kouchuu Ouja Mushiking Super Collection
3. Card de Asobu! Hajimete no DS (a child-friendly educational game)


For Dinosaur King no.
It does have an NDS game but I don't know why SEGA didn't make it card reader based one for this.
