Props for showing vids where you lost.
Video 1 :
2 lols. Lol, can't sidestep din's fire... >.<. Lol, didn't punish the transformation because she was still invincible.
Notice how Zelda began to perform din's fire in the air more often? You challenged her din's fire with tjolt many times. It worked sometimes, you shielded, she got hit.
So then she just jumped and did din's fire. In that position she could advance while you're shielding or wait for and punish your eventual retaliation. And most of the time din's fire > tjolt.
That being said do similar. FULLhop your tjolts, this way you can retreat, advance, etc, but switch it up with DJing your tjolts. Retreat with a QAC > tjolt.
Stay unpredictable.
Whenever you got close after a barrage of din's fire spam, Zelda would use dtilt or Fsmash you many times, or sidestep > something. She's expecting you to do something, and you're getting punished for it.
Don't fully charge your skull bash when your on the stage. REALLY predictable and punishable. >.<
Video 2 :
You messed up the chain grab.
More chain grabs.
With a character that outspaces you, it helps to be in their face and agressive so that the outspacing does count but the predicting and mindgames does.
Very good with predicting his recovery though.
Sry, but I'm tired so that's all I got to say for now...