Before Tyrone can get close to him, Snow entire atmosphere has become dangerous and dark causing Steve who is nearby to straighten up while instantly becoming alert as his entire instinct screaming danger and for him get away fro the person before him.
It provides Steve great evidence that Leo's lover is absolutely deadly and terrifying in the same sense as his friend.
With his lip thinning in a straight line, Snow raises his hand to stop older brother from getting closer, making Tyrone extremely confused when the usually bright emerald eyes brimming with soft and kind expression has turned cold and indifferent, completely so different from the one he met and interacted from before.
Suddenly the extreme happiness and delight of learning about his younger brother to have been alive and well this entire time have stopped when he saw the aloof and distant gaze of the person standing before him.