If something supervened, it happened as a result of something else.
Supervened is a serious word. It is often used in serious talks or in science.
Examples:
The fight supervened because of the argument.
The rain supervened after the clouds came.
The party was fun until the rain supervened and everyone had to go inside.
The cake was good, but then the supervened and it fell on the floor!
The supervened and made everything better.
The supervened and changed everything.