Vastupidiseks
Vastupidiseks is an Estonian translative form of the adjective vastupidine, meaning opposite or contrary. In grammatical terms, vastupidiseks denotes a change of state into being opposite, or into opposition, and is formed by adding the translative suffix -ksi to the stem vastupidine. The form is chiefly found in linguistic descriptions, grammars and dictionaries, and is less common in everyday speech, where other constructions are used to express opposition.
Etymologically, vastupidine combines the notion of being against or contrary with a descriptive stem, and vastupidiseks
Usage notes: vastupidiseks is typically used with verbs of becoming, such as muutuma, or in predicative constructions
Examples: Ta muutus vastupidiseks varasemast seisukohast. (He became opposite to his previous stance.) Läbirääkimised muutusid vastupidiseks,
In summary, vastupidiseks is a specialized grammatical form used in Estonian to express turning into an opposite