Some subtle Brilliance comes from John being called the "Baba Yaga". If one remembers, depending on the story, the Baba Yaga was a very feared entity, The Dreaded if she were crossed, and treated as something of a bogeyman. In a sense, given that Viggo said John was the one "you sent to kill the fucking boogeyman", he's seen as more dreaded than the feared Baba Yaga.
When John kills Iosef, there's some fridge brilliance in how he blows up the escape vehicles. The vehicles explode after he starts shooting the guards outside, indicating that John snuck into the building, planted the bombs, then snuck back outside and started killing the guards with the sniper rifle. He wanted Iosef to feel terror and know John was coming for him, and to cut him off from all of his men by killing them one at a time before finishing him off. While he does finish Iosef off with brutal efficiency, the lead up to it was him deliberately cutting Iosef off from escape so that the puppy-killing bastard could feel the same fear and helplessness that John felt, right before the final gunshot.