I really hate pain

Asch is half of a pair of perfect isofons (actually, it's technically a trio, but one member is a particle energy god and way less likely to be relevant). As such, he has a connection to his replica (Luke fon Fabre) that would probably ping Soubi's bond sight. It probably appears to be a flow of golden particles (obviously Seventh Fonons, if Soubi sees them used in a more normal context); when both are in game it's a somewhat distinctly one-sided flow from Asch to Luke, at least unless they get the sliiiiiight problem with it fixed.