A Dirge Parody
Benjamin D. Sommer notes Isaiah 14 is written in qinah meter typical of a dirge or lamentation:
14.1-23: A mock lament concerning Israel's oppressors The poem in vv. 4b-21 describes the ignominious death of an Assyrian monarch of Isaiah's time, probably Sargon II, who was killed in battle in 705. It was later reinterpreted as predicting the death of a Babylonian monarch...4a-23: Each Heb. line in this poem divides into two halves, the first with three main beats, the second with two. this meter, often called qinah (dirge) meter, is typical of dirges (such as 1.21-27 and the poems in the book of Lamentations); it also occurs, as here, in mock laments (another such mock is found in Isa. ch 47).
In her paper, Gale A. Yee goes further and compares Isaiah 14 to David's lament for Saul and Jonathan (2 Samuel 1:19-27) and concludes Isaiah “deliberately parodied the solemn dirge form...in order to ridicule the tyrant and foretell his ignominious defeat.”
2 The form of the dirge is made up of 5 strophes: Strophe I: vv 4b-8; Strophe II: vv 9-11; Strophe III: vv 12-15; Strophe IV: vv 16-19; Strophe V: vv 20-21.
3 Thus, the verse in question should be placed in context of Strophe I:
4ayou shall recite this song of scorn over the king of Babylon:
4bHow is the taskmaster vanished, How is oppression ended!
5The LORD has broken the staff of the wicked, The rod of tyrants,
6That smote peoples in wrath with stroke unceasing, That belabored nations in fury In relentless pursuit.
7All the earth is calm, untroubled; Loudly it cheers.
8Even pines rejoice at your fate, And cedars of Lebanon: “Now that you have lain down, None shall come up to fell us.” (NJPS)
Verse 6 begins with מַכֶּ֤ה which the NJPS renders as "that" not "he." The NET takes a similar approach and gives an explanatory note:
It  furiously struck down nations with unceasing blows. It angrily ruled over nations, oppressing them without restraint. (NET2)
9 tn Or perhaps, “he” (cf. KJV; NCV “the king of Babylon”). The present translation understands the referent of the pronoun (“it”) to be the “club/scepter” of the preceding line.
The decision to use "it" or "that" rather than "he" refers back to the preceding text:
The LORD (singular) has broken the staff (singular) of the wicked (plural), The rod (singular) of tyrants (plural) (14:5)
שָׁבַר יְהוָה מַטֵּה רְשָׁעִים שֵׁבֶט מֹשְׁלִֽים
Tyrants is plural where מַכֶּ֤ה ("it/he") is singular. If rendered as "he," it more accurately would be seen as referring to the LORD not the tyrants. That is how the LXX translator conveyed the passage:
The Lord has broken the yoke of sinners, the yoke of princes. Having smitten a nation in wrath, with an incurable plague, smiting a nation with a wrathful plague, which spared not, he rested in quiet. (Isaiah 14:5-6 LXX)
If it is "he," then it is the LORD who acted. In other words, translations like the King James which render "he" but attribute actions to the tyrant do not follow the logic of the text.
The Scepter of Tyrants
When rendered as "it" מַכֶּ֤ה refers to the instrument which passes from one ruler to the next:
In Isa 14:5-6, it is not a question of weapons but of the staff and scepter, symbols of a ruler’s power and dominion. However, in the case of our tyrant they represent metonymically his abuse of power and his oppression…The second way in which the poet parodies the dirge form in describing the tyrant’s life is through the participial and appositional style of these verses. In true hymnic laments, this style is meant to praise the individual. Here, however, this style functions as a bitter accusation against the person: the tyrant’s scepter “had struck the people in rage, blows without ceasing, had governed the nations in anger, persecution without respite.”
The dirge is addressed to Babylonian tyrant, but it aptly describes the earlier Assyrian ruler. Yet there is one scepter which passes from one ruler to the next which "struck the people in rage, blows without ceasing, had governed the nations in anger, persecution without respite."
1. Benjamin D. Sommer, The Jewish Study Bible, Oxford University Press, 2004, p. 812
2. Gale A. Yee, Anatomy of Biblical Parody: The Dirge Form in 2 Samuel 1 and Isaiah 14, Catholic Biblical Quarterly, 50, 1988, p. 565
3. Ibid., p. 574
4. Ibid., p. 576