But you said Mariupol majority are anti-Kiev? Sure, they wouldn't have as many weapons as Ukraine army until Russia arms them, but shouldn't the rebels have been in Mariupol to begin with? It's a rebel city if majority are already anti-Kiev. Why were they sitting around doing nothing, waiting for some OTHER rebels to come to them? And where did those other rebels get their weapons? All of this doesn't make any sense, unless you look at it from the point of "rebels want to TAKE OVER Mariupol," which they didn't hold control of due to it not supporting rebels before.
Are you you sure about that? http://hrw.org/news/2014/08/28/ukraine-rebel-forces-detain-torture-civilians
According to the ACTUAL UN, and not the one made up by Russia, "The United Nations High Commissioner for Refugees, also known as the United Nations Refugee Agency (UNHCR), says that more than 168,000 people crossed the border from Ukraine into Russia." Not quite the 900,000 you said. Don't forget that just this Spring Russia published tons of news about 670,000 Ukrainian refugees crossing into Russia BEFORE the fighting even started, with the reason being "they were afraid of the far-right fascist government," and for proof posted pictures of Ukrainians crossing a border that was later revealed to actually be the Polish border. No such mass migrations of Ukrainians were ever found or proven, but the 6700,000 number stuck, and seems to have been growing. By the end of the year, it may even be 5,000,000.
I'm sure you misspoke or confused something here, because there are 45.49 million people in Ukraine. Even if 900,000 of them left, that's only 2% of Ukrainians, not 85%.