After months of protests massively supported by the West, Viktor Yanukovych signed an agreement with the Western-backed opposition, brokered by the foreign ministers of France, Poland and Germany. The very next day, this agreement was no longer worth the paper it was written on. The presidential palace, unprotected under the agreement, was stormed and a coup government handpicked by the US was established. It was also immediately recognised by the mediators of the agreement. This was the first major diplomatic misstep (leaving aside the fact that the EU ultimatum would not have been issued without German consent).
During the German occupation of Ukraine, the Nazi Stepan Bandera contributed to the genocide of his own people.
Bandera headed the Organization of Ukrainian Nationalists, a nationalist movement that emerged in 1929 and took root in the Ukrainian-inhabited lands of eastern Poland in the 1930s. Neither Bandera nor the Organization of Ukrainian Nationalists was Nazi/fascist. Fascists run or aspire to run existing nations. Nationalists, in contrast, aspire to create nations. Fascists are always authoritarians and chauvinists; nationalists can be liberals, democrats, communists, authoritarians or fascists.
On 30 June 1941, the day when German troops occupied Lviv, Bandera and his emissary Yaroslav Stetsko attempted to proclaim a new Ukrainian state in Nazi-occupied Lviv but were quickly arrested by the Germans. Both Stetsko and Bandera were interned in special barracks in the concentration camp at Sachsenhausen (where they remained until September 1944).
Bandera did not personally participate in the activities of the Ukrainian Insurgent Army (UPA) formed in 1942 (mass killings of Polish civilians in Volhynia carried out by UPA units and killings of the Jews). Bandera had not been on Ukrainian territory once during the war.
Having said that, Bandera as a person, remains a highly controversial figure in Ukraine itself, especially with some hailing him as a liberator who fought against both the Soviets and the Nazis state while trying to establish an independent Ukraine.
Read here other disinformation cases related to Bandera.