Super hardening is what happens when you combine your special abilities (df, genetics etc) with your haki.
Luffy calls his vulcanization.
Kata blocked mochi
Jinbei Shark something.
I don't think it's fully advanced but for sure it's like level 1.5.
It'll get though destroyed by people who use flow if the two fighters are comparable. I don't see though how tashigi using flow (and she does) can bypass Jinbei or Katas defense