As the topic.

Looking at the faq dosent provide much help, my gut reaction is that as a lasting effect was created when the event came into play as a character blanking the text after the fact will change nothing, it will keep the keywords, text and icons that were specified when it was played. Or is the text a constant requirement for the event to be in play as a character (like blanking a maesters traits make their attached chains fall off).

Any help appreciated.

Imagine that instead of saying "put this card into play as…", the event said to "put the top card of your deck into play, face down, as…". What will happen to that "token character" after the event text resolves and is put in the discard pile? Nothing, right? Because the effect that created the token character has already completely resolved. The text of the event is not needed to keep that token character in play.

The fact that the event puts itself into play as the token character rather than some other card doesn't change the fact that the effect that creates the token character has already completely resolved, so the event's text is no longer needed.

So yeah, you're right that the event's text is not a continuous effect that needs to be continually active to keep the event a character. Once the effect turns the event into a character, it stays a character (with whatever stats it was created with) until something specifically stops it from being a character.