I don't know how Mad Dog did it, but he won.
Yuri is still struggling to maintain a façade of calmness, not wanting to reveal his anger and disappointment.
After finally finding a path to the heavens, after finally coming upon a staircase to the skies, just as Yuri began to demonstrate his worth, before he had the chance to truly transform, before he could climb onto the rapidly moving car behind Hunter, Mad Dog disrupted all his plans once again.
Yuri knew that Mad Dog always wanted to take him out, that Mad Dog had been searching for him, but after establishing a relationship with Hunter, Yuri felt invincible against Mad Dog.
Mad Dog's power comes from the United States, those shadow forces spread across the military and intelligence sectors – that's Mad Dog's greatest reliance.
Yuri only wants to obtain a power more dominant than Mad Dog's, to completely overshadow him; once he uproots Mad Dog, victory will naturally come without a fight.