The buffs that the wind mystery removes are the passives that activate at the beginning of the match. Like Iruka shields + 40% Attack and Ninjutsu buffs. It doesn't remove buffs from mysteries and barriers.

It could be that they are treated as an attack instead of a shield/buff kinda how Ao is when he is using his skill. Like Izanagi effect doesn't proc unless a condition is made, but im only guessing.

i knew about izanagi not beeing purge able with the mystery but i didnt know that lightning armor too is not purged by it

Here is another weird example.
When you use the mystery on Hinata, whom has her mystery on already, it will * away the super dodge part while the taunt part still intact. Long story short, Hinata will still get all the normal standard attack but can't dodge them at all
So, this case prove that Wind main's 4th mystery can remove buff from other mysteries, right ?
Any mod with better knowledge can clarify this ?

Hey

Yes, it removed complete buffs/debuffs from characters, regarding of mystery or not.

Things like Izanagi isn't considered a buff. It's a situational mystery that only actives upon a certain condition.
Similar to Lightning Main's Lightning Armor. It grants immunity to upcoming debuffs.

Conditional based skills usually remain unaffected by Wind Main's 4th Mystery unless it grants an immediately buff/debuff etc.

Hope that helps.