Ridging above the world and sky-encompassing,
--- “横空出世”是虚写，不是很好翻译。

the monstrous Kunlun mountain,
--- “莽昆仑”之“莽”非 monstrous也，“莽”，阔大浩远也。

has witnessed the entire mankind's vicissitude and spring scene.
--- 觉得“vicissitude”和“springscene”并不平等。说“阅尽人间春色”固然是指“人世变换”，则不如单写“变换”。

Sending millions of snowy dragons up flying,
---- 哈哈，好！穿越！昆仑是龙的基地。

altogether freezing the heavenly space.
--- 越来越精彩！雪山之龙，能冻住万物！

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

overflowing rivers,
--- 江河横溢，精炼。直译可也。

drowning humans like fish and and tortoises.
--- 哈哈，太直译了。毛太祖直写，豌博直译。

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

And now I say about our Kunlun mountain:
--- 介句不准，不是say about，而是对昆仑下命令也。时毛太祖御国多年，颇多“帝语”。哈哈

too high in elevation,
too much snow accumulation.
--- 毛太祖竟以为天道可人制，其实不然尔。人何能为？

May I wield a super long double-edged sword,
slicing you into three portions?
--- 译得好！跟切面包一样。其实毛太祖这句来自完颜亮的“虬髯捻断，星眸睁裂，唯恨剑锋不快。一挥截断紫云腰，仔细看、嫦娥体态。”不过后者是断云，而老毛要截山。哈哈。得天下的就是王者之作，被杀了的就是狂言了。

Awarding one portion to Europe,
one to the US,
and the other to the eastern nation.
--- 那时候毛太祖没少援助非洲的黑鬼们。

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.
这三行忒夸张了。哈哈。愚意可以缩减而一带过之。“环球同此凉热”就是共产主义么。或孙中山之“天下为公”？实现也难。

再赞豌博译笔功力！介首比较难，俺稍迟再译。正试图翻译完颜亮那首涅。