I saw this in a really old thread (page like 79) from two years ago, so I just wanted to confirm it.

Whispering Wood sets up a lasting effect in the plot phase that lasts through the end of the Epic Phase, so even characters who are immune to events (like TRV, if he had lost an icon lets say, or my opponents Sansa Stark with Crown of Winter attached) can be killed?

More to the point, the event is not working directly on the characters. It is working on the structure of the game. Immunity only protects from direct effects. Since Battle of the Whispering Woods is not directly affecting any characters that dies in the Epic Phase, you cannot sidestep the death through immunity to events. If you could, wouldn't the entire Epic phase not apply to event-immune characters, so they couldn't, for example, participate in the challenge?

That was what I thought, but I just wanted to confirm, thanks ktom