It is very sad about what happened in Odesa a year ago.
However...
it was the pro-Russian group who started it. People from the Ukrainain crowd were the first to die, but by the end of the day, the pro-Russians took the worst of it.
Btw, your chronology is off by saying that Odesa tragedy (on May 2) led to “civil war”. Russian FSB colonel Girkin advanced on Sloviansk in mid-April, and Russian specnaz taking over Ukrainian government buildings in Donetsk and Luhansk was even earlier. So it would make a nice narrative if Odesa preceded all that, but the dates don’t match.
Russian attacked a peaceful march.
“They were sparked when a group of masked pro-Russia activists allegedly led by Sergei Dolzhenkov, a former police officer known as “Captain Kakao”, attacked a pro-Ukraine march mostly made up of football fans. The pro-Russia men were armed with clubs, fireworks, homemade grenades and guns. The first person to die was 27-year-old Igor Ivanov, a pro-Ukraine member of the extreme nationalist organisation Right Sector. He was gunned down on Odessa’s main street, Deribasovskaya, lined with cafes, bars and restaurants and usually thronged with tourists.”