Where does “ворожій” come from?

ворожій (Ukrainian) comes from Ukrainian -і́й, from Latin -ium, from Latin -ius, from Proto-Italic -jōs, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “ворожій”, step by step

Step	Language	Word	Meaning
1	Ukrainian	-і́й	er, -or, -ist
2	Latin	-ium	Suffix used to form abstract nouns, sometimes...
3	Latin	-ius	forming adjectives from nouns; nominative neuter...
4	Proto-Italic	-jōs	Forms comparative adjectives
5	Proto-Indo-European	-yós	Creates adjectives from noun or verb stems

Every word from Proto-Indo-European -yós →Every word from Latin -ium →Every word from Latin -ius →