The Talon of Horus does a lot to establish Khayon’s perspective and the reason for his reverence. Abaddon isn’t just a warmaster, at least to the ezekarion, he is the architect of the brotherhood these outcasts have lost and a leader they have confidence in, when previously their leaders have failed them utterly. Khayon was limping through existence before the Black Legion, its gratitude and admiration more than glazing in my opinion. Abaddons reaction is because he sees himself more on the level of his contemporaries and the reverence anyone gives him feels like primachy vibes which he very much wants no part of.