It seemed to his friends that his attitude was of a puzzling nature.这句话错哪儿了?

TO his friends 位置放错了.应该放到最后.感觉你说的好像对~~但是to his friend 放到句末感觉意思和原句表达不一样了啊是不一样了，原句的句型就是错的，我觉得意思肯定会变。不过就句子意思来看，it 应该就是代指 That 后面的内容。