In the Bliss World of the Great Joy Arhat, he was like a deity because this world was connected to his Primordial Spirit, and it could even be said that the Bliss World was an embodiment of his Primordial Spirit.
The Bliss World could dissolve Su Xin's memories, so naturally, it could also probe into them.
Just now, when the Great Joy Arhat clashed with Su Xin, he had experienced some of Su Xin's formidable martial arts and secret techniques, and acquiring these would be a significant gain for the Great Joy Arhat.
Actually, the Great Joy Arhat wasn't interested in the powerful sword techniques Su Xin possessed, as he wasn't a sword cultivator.
But what really made the Great Joy Arhat envious was the Battle Body that Su Xin displayed at the end.
The Esoteric Sect and the Shaolin Temple may have branched into two, but their cultivation techniques still had some commonalities.