Viscount Bast must have found out, through some means or experienced some sort of strange adventure, that Byrne possessed the odd destiny of the "Treasure Key".
To unlock some sort of gate or palace, Seal, or other similar things, he desperately needed Byrne to willingly sacrifice his life to activate the destiny's trajectory of the "Treasure Key" to help him.
Therefore, Viscount Bast had always been very good to Byrne, playing one emotion card after another without holding back.
Because he understood very well how much Byrne valued emotions!
The invisible threads of the "Treasure Key" destiny's trajectory were different from other ordinary destinies; they faintly emitted a golden glow, and after staring at them for a long time, a golden key's mystical illusion would appear.
"Unfortunately, the parts that Bast lent to the Fischer family did not possess Spirituality; even if they did, Byrne and the others would never dare to sacrifice Bast's belongings to me."