"Look at target face-down resource an opponent controls. If it's a non-ongoing plot twist, you may turn it face up."


Does this mean the plot twist becomes useless? Can my opponent activate it?

if it's a non ongoing pt then it becomes useless, if it's an ongoing plot twist it doesn't.

Can my opponent activate the plot twist when i activate nine lives?

Before Nine Lives can resolve both players have to pass. So yes your opponent can flip twists before you get to look.

Thanks for clearing that up.