What about the error state?
If I try to express like below situation, I can not add two onClick events, so I have to make some wrapper frame or something in Prototype.
Login Button ->onClick -> Error Dialog
-> Success Dialog
In this case, the new Starting point also can not handle it. Event dependent from Starting point is a passably good option, maybe?
For Example, in the below case, I can have multiple onClick but dependent on the Starting point.
Success Starting Point -> -> onClick -> Error Dialog
Login Button
Error Starting Point -> -> onClick -> Success Dialog