The words "terrifying" and "fearsome" share similar meanings. Together they emphasize the fear that the Chaldeans instilled in other people. Alternate translation: "They cause others to be greatly terrified" (See: [[rc://en/ta/man/translate/figs-doublet]])
The word "splendor" represents their pride in how they view themselves. Yahweh speaks of their opinion of themselves as if the qualities of judgment and splendor came from them. Alternate translation: "because they are prideful, they decide for themselves what judgment looks like" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])