U+0454 Cyrillic Small Letter Ukrainian Ie

The Wikipedia has the following information about this codepoint:

Ukrainian Ye (Є є; italics: Є є) is a character of the Cyrillic script. It is a separate letter in the Ukrainian alphabet (8th position since 1992, 7th position before then), the Pannonian Rusyn alphabet, and both the Carpathian Rusyn alphabets; in all of these, it comes directly after Е. In modern Church Slavonic, it is considered a variant form of Ye (Е е) (there, the selection of Є and Е is driven by orthography rules). Until the mid-19th century, Є/є was also used in Romanian and Serbian (the letter was eliminated in Vuk Karadžić's alphabet and replaced by digraph је). Other modern Slavonic languages may use Є/є shapes instead of Е/е for decorative purposes. Then, the letter is usually referred to by the older name Yest (which also refers to the conventional Ye). If the two need to be distinguished, the descriptive name Broad E is sometimes used (in contrast with "Narrow E").

In Ukrainian, Є/є commonly represents the sound /je/ or /jɛ/ like the pronunciation of ⟨ye⟩ in "yes". (See usage for more detail.)

Ukrainian Ye is romanized as ⟨je⟩, ⟨ê⟩, or even ⟨e⟩. See scientific transliteration of Cyrillic.