What are the creative characteristics of "Four Spirits School" and "Jianghu School" in the late Southern Song Dynasty?

In the late Southern Song Dynasty, the national situation declined gradually. Jiangxi poetry school has lost its superiority, and the later poetry schools such as "Siling School" and "Jianghu School" all showed their unique styles. At the end of the Southern Song Dynasty, there were frequent wars and border troubles, and patriotic passion became the mainstream of the times. Before and after the demise of the Southern Song Dynasty, a group of politicians and military strategists emerged, who were able to write poems and articles with only one purpose, blowing the horn against the enemy and expressing patriotic passion. Their poems written with blood and tears show the unyielding character of the Chinese nation and are brave in dedication, which has written a glorious chapter in the history of literature. Among these patriotic poets, Wen Tianxiang, Xie Ao, Wang Yuanliang, Xie Fangde and Zheng Sixiao are the representatives, and they all left colorful works.