Upon returning to St. Petersburg, he studied painting and sculpture in the private studios of Dmytro Kardovskyi and Jan Ciąglińskyi, as well as at the Baron Stieglitz School of Technical Drawing.
In the period of his fascination with the avant-garde, he experimented with various directions of avant-garde painting. Together with Sofiia Baudouin de Courtenay (a student of Mykhailo Boichuk during his Paris period) and artist Mykhailo Le-Dantiu, Sahaidachnyi promoted “the idea of the primacy of the primitive and folk art in art”. On Sofia’s advice, he came to Lviv, where he met Mykhailo Boichuk and was introduced to Boichuk’s “Neo-Byzantinism.”
In 1917, after moving to Kyiv, Sahaidachnyi became a theater artist and entered the Ukrainian Academy of Arts, where he studied in Boichuk’s workshop.
Each period left a distinct imprint on his work: sketches of Hutsul life and architecture, portraits of Hutsuls, landscapes of the region, concise color works in the spirit of the avant-garde, paintings in the style of the Boichuk school, as well as Cubo-Futurist sculpture and decorative works.
He was a founding member of ARAU (Association of Revolutionary Art of Ukraine), organized in 1925 alongside Davyd Burliuk, Anatol Petrytskyi, Mykhailo Boichuk, Vasyl Sedliar, and Ivan Vrona.
Sahaidachnyi’s creative search also manifested in sculpture, which has been described as “Cubo-Futurist Boichukism.” Unfortunately, many of these compositions were destroyed during the campaign against “anti-people formalism.” The mass repressions against Ukrainian cultural figures in 1932 forced him to relocate to Luhansk. Works he exhibited in Luhansk and Stalino in 1934–1935 were condemned as “formalism.” However, authorities failed to accuse him of “Ukrainian bourgeois nationalism,” which saved his life during the tragic year of 1937.
Deeply enamored with Hutsul art (in 1946 he moved with his family to Kosiv), Sahaidachnyi began collecting works by both renowned masters and talented contemporaries.
In the mid-1950s, together with Boichukist artists Serhii Kolos and Okhrim Kravchenko, he initiated plein air painting trips to the picturesque landscapes of Yavoriv, Yaseniv, Richka, Brusne, and Pistyn. One August morning, at the age of 75, Sahaidachnyi set out with his beloved sketchbook into the mountains. His heart, however, could not withstand the heat and the long road. In 1969, a posthumous exhibition of his works was organized in Lviv.As an educator, he worked at the Mezhyhiria Art and Ceramics Technical School, the Hohol Art and Industrial Technical School in Myrhorod, and at art institutions in Dnipro, Nizhyn, Luhansk, and the Kosiv Art School. He taught sculpture, drawing, painting, and art history.The works of Yevhen Sahaidachnyi are preserved in the National Museum of Hutsul and Pokuttya Folk Art named after Yosafat Kobrynskyi, the Andrey Sheptytsky National Museum in Lviv, and the National Art Museum of Ukraine (NAMU), which houses five paintings and one graphic work from his Boichukist period.