Netflix’s Sonic Prime ending explained

Nine has one of the most tragic arcs in Sonic Prime, with a completely different backstory from Tails. Unlike how Tails met Sonic in the original universe, Nine didn’t have anyone to grow up as the Council took over New York City, leaving him a distant and dark loner who trusts no one. Thus, when Sonic first meets Nine, he is treated rather coldly until he is eventually able to win Nine over to his side. However, after Sonic declines Nine’s request to travel to a new world and start over, Nine is visibly unhappy and feels some of his old feelings resurfacing.

He is especially annoyed when Sonic suddenly disappears several times after touching a prism shard, making him feel abandoned. So when he talks to the Chaos Council about potentially working with them to improve their Shatterverse tech, you can’t help but wonder if Nine really plans to betray Sonic. Perhaps this is just a momentary oversight: Nine’s feelings of abandonment are certainly real, but he never seemed capable of outright villainy. Also, every time he felt like this in the past, he quickly made a turn to help Sonic, so it’s not surprising if it happens again.