So we learn that Kass's teacher that he has been talking about for a while was a Sheikah musician who had feelings for Zelda, but...
"Escort"... "own knight attendant"... yep, that's definitely Link.
And Zelda "only had eyes for her escort"... Whoa, whoa, whoa, Zelda has feelings for Link?
Turns out she really does, as these next couple of lines from Kass state reveal so:
Kass says it all:
Princess Zelda was in love with Link! Those feelings she had for him was how she managed to awaken her Hylian powers. Ladies and gentleman, the BW!Link and BW!Zelda ship is officially canon!
And yes, I know this isn't the first time Princess Zelda had a crush on Link. Skyward Sword was explicit about the romance between the two through their interactions with each other, but the reason I'm getting excited over Kass's words is because it confirms some suspicions a lot of us had when we first saw that crying scene. What also makes this love from BW!Zelda different from SS!Zelda is that BW!Zelda initially hated Link, whereas SS!Zelda never showed any disdain for him.
On a minor note, it terms out all those rainbow-colored Rito children that helped in that one shrine quest are Kass's daughters. I didn't think he'd have this many kids! We also learn the song he's been playing on his accordion this whole time was the very song is teacher passed onto him.