Ukrainian President Volodymyr Zelensky on Saturday countered an appearance by his Russian counterpart Vladimir Putin at a Moscow stadium with a grim message of his own. It came a day after Putin praised the “special military operation” in Ukraine as a “heroic” mission by the Russian army during a patriotic rally at Moscow’s Luzhniki Stadium before tens of thousands of cheering Russians. The 100,000 people in front of the stadium, along with 95,000 in the arena itself corresponds to around the number of Russian soldiers who have entered Ukraine, Zelensky said on Saturday morning in a video mess…