Rules FAQ

You compare the printed strength of both characters -- the unique Stark character being killed/sacrificed and the opponent's target character. Strength modifiers change effective strength, but not printed strength (the ink on the card).

Duplicates can save from any effect that makes the character leave play, including "Shuffle into the deck".

Tears of Lys kills a character outside of the challenges phase, so you cannot react with Winterfell Crypt.