What was Ni Zan's calligraphy achievement in history?

Ni Zan works in calligraphy and is good at regular script. His calligraphy, as a master of wild rhyme, participated in Zen and learned Taoism, and traveled all over the world. With the charm of ice and snow, he wrote his unique style of simplicity, simplicity and lightness. Wen Zhiming and Dong Qichang both spoke highly of his calligraphy. Wen Zhiming commented: "Mr. Ni's personality is noble, and his enthusiasm has the spirit of Jin and Song Dynasties." Dong Qichang commented: "Old innocence, Mi Chi (that is, Mi Fei) is only one person short." Compared with Ge Shoutie's calligraphy, Ni Zan's calligraphy is completely different in style, which inevitably leads to criticism. Ruxiangmu accused Ni Zan of being bitter and shabby when he wrote it. Even in the year of Lao Peng, there will be no good in the end. Li Ruiqing, a modern calligrapher, said, "Ni Yushu is cold and barren, without losing the momentum of Jin people, and there are disadvantages in the forest." For example, there is a profound understanding in the poem (Tao Yuanming), but it is not something that meat eaters can solve. Ni Zan's works handed down from generation to generation include Three Stamps, A Boat at the Beginning of the Month, A Poem Post in the Guest Hall, Chen Shi Juan, Poems with the Same Rate, Poems with the Same Style, Cautious Words in Two Bamboo Slips, Miscellaneous Poems Post, etc.