וְנִשָּׂא הֶהָמוֹן וְרָם לְבָבוֹ וְהִפִּיל רִבֹּאוֹת וְלֹא יָעֽוֹז׃
And when the multitude is taken away, his heart shall be exalted, and he shall cast down tens of thousands, but he shall not prevail. [ESV]
In the Hebrew, it's a bit easier to see the relationship between "be exalted" and "cast down." Both have meanings that could also refer more literally to directions. Their combination in this context, with opposing forces going different ways (the king's heart is exalted while his enemies are cast down), provides an added degree of emphasis.
I also noticed a small feature in the Vulgate:
et capiet multitudinem et exaltabitur cor eius et deiciet multa milia sed non praevalebit
The phrase "multa milia" (many thousands) alliterates, and the repetition involved lends a small sense of this abundance.
