What Happened?!
As a mortal, Lucian could kill someone at the mid-stage of Body Strengthening Realm. It just showed how extraordinary his physique was.
And now that he finally entered and became a Qi Gathering Realm cultivator, each time Spritual Energy completed a Grand Circulation, his physique became more robust. Not only that, but his Spiritual Energy was being transformed into Crimson Flame Spiritual Energy as a result of his cultivation technique, further refining his body.
But of course, there was still a limit to how much strong his current cultivation could make his body.
However, that was still not enough to kill someone like Xander, a peak mid-stage Qi Gathering Realm cultivator.
Though Lucian was unaware of Xander's current cultivation, the fact that he came to kill him despite knowing that he was capable of killing cultivators as a mortal demonstrated Xander's confidence.