feared is another thing.. and as for kin gin brothers is simple they go into kuubi form and mei runs for her life bcoz no acid , corrosion effects , seen naruto in that form he just goes attacking no matter what attack the opponent does.. the chakra itself is a gr8 shield...
im going to lump both responses into one.
First you have no clue what you are talking about when you say zabuza can turn into mist.... No he cannot, and i'd LOVE to see the manga saying or showing this technique. he creates mist that looks like his chakara and uses his other senses to attack. Simple.
Second, her mist can corrode Susanno, the ultimate shield. Which means it can corrode some of the nine tails chakara in an armor form. The Kages are so much stronger then the people who actually fought them, they would be killed. Hell, Onoki could use his dust elemental