Despite San's words, he was actually quite surprised, shocked even, at this turn of events. It was most likely what made his wide grin eerier.
With the way things were starting to turn out, there should be way more pain evident in his visage, and yet while he did not show it, Evian felt a lot of pain and a lot of anger that was all directed at the one who had caused this.
They were all directed at the Malevolent One.
Once Darryl and Marlon showcased abilities like those of the Malevolent One's representative, he truly wondered if one of the two or someone else of the Edgar family could be the Malevolent One.
However, he felt if that was the case, there would have been more graceful means of robbing the Confluence so he concluded that it was most likely someone who got to the brothers to get to the Confluence.
After all, once the location of the Confluence was known, half of the problem had been solved.