Hi,
Unity 2d: no, cause they don't have any delegates.
Ngui: indeed, it's totally possible, you can use ngui delegates to create bridges with playmaker. A PlayMaker custom action can register delegates from anywhere really, there is no restricitions here. Also, you have to be aware that them this delegate needs to be properly dismissed when the action exits, and also the obvious fact that it can not be a "global" system within a fsm, it can only be for a specific state, which is why I went for proxies, cause then I simply fire an event to a fsm, which is a lot easier to implement and deal with in most cases then having to implement a specific fsm dealing with a particular event in a particular state and do all this tedious work anproxy do just fine.
Bye,
Jean