Trystan, an Early-stage Elemental Gathering Realm cultivator was killed by an Early Stage Dantian Formation Realm cultivator. If this news was spread to the Belmont Subcontinent, then no would believe such a joke.
Alex may have had the help of a peak Grade Rank 2 Demon Beast but still, the fight shouldn't have ended like this.
Alex very well knew, if not for illusion ability he obtained from his bloodline, then he would have to fight a life and death battle with only a fifty percent chance of winning and ending the fight with grave injuries.
As for why he didn't use his ability in the beginning, it was because of the cultivation level gap between them. Higher-level cultivators have a higher resistance to soul attacks and the time to keep them in illusion is reduced considerably.
Trystan was not like Merchant Goerge, he was an assassin with a trained mind. He could possibly have come out of the illusion with some extreme methods such as hurting himself.