Ridging above the world and sky-encompassing,
--- “橫空出世”是虛寫，不是很好翻譯。

the monstrous Kunlun mountain,
--- “莽崑崙”之“莽”非 monstrous也，“莽”，闊大浩遠也。

has witnessed the entire mankind's vicissitude and spring scene.
--- 覺得“vicissitude”和“springscene”並不平等。說“閱盡人間春色”固然是指“人世變換”，則不如單寫“變換”。

Sending millions of snowy dragons up flying,
---- 哈哈，好！穿越！崑崙是龍的基地。

altogether freezing the heavenly space.
--- 越來越精彩！雪山之龍，能凍住萬物！

Snow melting away in summers,
--- 夏日消融，嗯，貼切。

overflowing rivers,
--- 江河橫溢，精煉。直譯可也。

drowning humans like fish and and tortoises.
--- 哈哈，太直譯了。毛太祖直寫，豌博直譯。

Regarding its historical sins and merits,
has anyone ever cared to assess?
--- 好譯！

And now I say about our Kunlun mountain:
--- 介句不准，不是say about，而是對崑崙下命令也。時毛太祖御國多年，頗多“帝語”。哈哈

too high in elevation,
too much snow accumulation.
--- 毛太祖竟以為天道可人制，其實不然爾。人何能為？

May I wield a super long double-edged sword,
slicing you into three portions?
--- 譯得好！跟切麵包一樣。其實毛太祖這句來自完顏亮的“虬髯捻斷，星眸睜裂，唯恨劍鋒不快。一揮截斷紫雲腰，仔細看、嫦娥體態。”不過後者是斷雲，而老毛要截山。哈哈。得天下的就是王者之作，被殺了的就是狂言了。

Awarding one portion to Europe,
one to the US,
and the other to the eastern nation.
--- 那時候毛太祖沒少援助非洲的黑鬼們。

The whole world will then be in peace,

these global imperialists,
please don't just envy our warmth,
they also deserve a serving of our chills we hereby experience.
這三行忒誇張了。哈哈。愚意可以縮減而一帶過之。“環球同此涼熱”就是共產主義麼。或孫中山之“天下為公”？實現也難。

再贊豌博譯筆功力！介首比較難，俺稍遲再譯。正試圖翻譯完顏亮那首涅。