In 2023, the government told Prigozhin, a head of a private military company Wagner, that he must transfer the command of his units to the main army. This resulted in Prigozhin taking his army from the frontline, capturing the headquarters of Special Operation in Rostov, and marching on Moscow. During march, they shot down several planes and helicopters which were trying to stop them. At that night, several private jets were urgently leaving the capital.

So, mistreating veterans might not work out as expected.

More details: https://en.wikipedia.org/wiki/Wagner_Group_rebellion

How did that end for Prigozhin? Where is he now?

He made a deal (not public) with the government, he leaves Wagner and gets out of Russia and the government leaves him alone. 2 months later a private jet with Prigozhin and several Wagner commanders exploded in the air in Tver Oblast, not far away from Moscow. There is video online of the plane breaking apart and falling if you search hard enough.

The deal seems to not work out.

I think there were no official explanation for this incident, propaganda posts explain that they were using drugs and playing with a grenade onboard.