The only one that I remember which I believe they even took out of the game was during the scene with Garuda. She states that she cannot temper you because you already belong to another, seeming to hint that Hydaelyn has tempered us and that is how we are granted the power of the echo. I feel this was thrown aside when they decided to go for the Hydaelyn/Venat is the ultimate most good there ever was without flaw or blemish.