Alright so I just got done reading chapter 721 and I have to say I was a bit lost for a while, but here's what I was able to get from it:
- Rebecca is a princess and her grandfather was the former king of what is now Dressrosa.
- The toy soldier knew who Rebecca's mother was and tried to protect her.
- The toy soldier practically raised Rebecca for the past 10 years.
This new information brings me to a new conclusion about the toy soldier's identity: I think Thunder Soldier is actually Rebecca's grandfather, the former king. Now before you shoot down my theory, let me explain my reasoning. We learned in chapter 717 that the toys were once human. We also learned that some of the toys had other reasons for wanting to spend time with certain humans. For example, one of the toys claimed he was this woman's former boyfriend but she did not remember him. Also there was the toy dog that said that little boy was his son and his mother was his wife but they don't remember him. This leads me to believe that Thunder Soldier is actually a relative of Rebecca's or at very least someone who was loyal to the former king and wanted to protect the royal family. But I'm gonna stick with saying he's the former king and Rebecca just doesn't remember him.
Well that's my theory, however I am sure there is some bit of information that I am overlooking so, go ahead, let me have it, shoot down my theory (cough cough... DP) or if not just let me know what you think.