Ravages of Time - chapter 521

to better appreciate the poetic character of the latest chapter, I shall turn to the passage from the Zhuangzi quoted in the chapter (and examine how Chen Mou played with it) 萬川歸之 Countless tributaries flow into it (the sea) without ever stopping in context, that section of the text discusses how rivers and streams however large they are miniscule when compared to the sea where they all find their place (and how the sea in its vastness reaches the 'drainage point' [尾閭] without being emptied, basically conveying how the dao is so much beyond whatever current or flow of thinking one has learned)

now that particular section of the Zhuangzi does not really talk about fish, and here Zhou Yu in his follow-up phrase [尾閭迎魚] inserts himself (due to the homonym between fish and his given name) and low-key brags a bit by claiming how in that point where all waters drain, the fish are welcomed (and that he himself is heading there, basically conveying how the schemes of all the other factions are limited in their framework, while he's attained a view beyond all that) however, when we turn our attention to the chapter title [尾閭無魚] it turns out, at that deep end, there are no fish to be found, not only conveniently reminding us that Zhou Yu's end is nigh, but also highlighting what his plan is really about (that is to say, in the larger scheme of things, a fish is but one other entity passing into and swimming across the great sea, and that it can continue without the fish)(edited)this also ties in to the notion of continuation the Sun clan has been harping about for so long... if it becomes as capacious and tolerant (given its acceptance of defectors such as Taishi Ci and Gan Ning) as the sea (with a bonus nod to its faction being a naval power) without relying on a single fish or being stuck on narrow currents and paradigms, it can last long.

-Poem: https://ctext.org/dictionary.pl?if=en&id=42145&remap=gb

There are two things in addition.

1. Cao Cao's appearance also served purpose. It was similar case with Guo Jia and it showcases how dependent he was on Guo, to contrast Sun clan. ( or in general, how Cao Cao's army, despite being a well-trained war machine, still features a great deal of involvement from the leader and his inner circle (making it possible for Zhou Yu to catch Cao Cao himself by surprise)

2. His pose (Head tilt, hands and etc) in a metaphorical sense may mean that he is swimming. Then comes the "camerawork" - on his background, there basically is a battlefield, which implies that he is swimming there and eventually goes up, in Heaven.

Now how this scene also represents the facet of its arc's main theme - going against the tradition

Fishes are supposed to swim in a sea, full of water and below the earth, as Zhou Yu was unbeatable at naval battles and similar stuff, but here we have a fish swimming on a mountain, full of fire. Also, Zhou Yu who was scolding Sun Ce all this time to not rush things, he himself was rushing for the whole arc. And in terms of plot development, death of an adviser/general means the annihilation of the morale, but instead his death raised the morale, because the faked his death so many times that the idea of him dying is already an ancient joke.