Based on the search results, there have been several changes and events related to the popular streamer known as Ninja. Here is a summary of what happened to him:

• In August 2019, Ninja left Twitch to stream exclusively on Microsofts Mixer platform).
• In June 2023, Ninja announced that he was leaving Twitch to join the up-and-coming streaming platform Kick.
• In September 2022, Ninja took a break from streaming after an incident in Fortnite cost him his Twitch verification.
• Ninja has also experienced health issues related to his eyes, which have required surgery.

In summary, Ninja has left Twitch twice, once to join Mixer and once to join Kick. He has also taken a break from streaming due to a Fortnite incident and has had health issues related to his eyes.