I think taunt, it's probably mistranslated. (P.S. the taunt skill in Chinese literally means protection, so.. defense skill?)

1. There is no such thing as "ignore defense skill" It's a mistranslated of "ignore taunt"

2. Sage Naruto does NOT ignore defense skill, nowhere does it say he does. Instead, sage naruto does NOT have a standard "attack". When he attacks, he is using one of his passive skill, which is more like a chase attack than it is a standard attack. Rotation does not work on it because rotation does not work on chase skill.