I must be missing something, as Riggs hasn’t called in his favor yet. Anyone who could enlighten me on how he works?
Seems to later unlock the side quest Deeper In Debt but found no way to trigger it yet.
You can get another item from him if you finish the main quest I think, but he hasn’t called his favor in, yet.
“Paying up for Riggs baubles” DLC confirmed 
I don’t trust the guy.
I haven’t taken his offer…
For my rp character at least 
I was let down that for being in his debt I got a vendor trash rare. Expected more.
I expected more as well, after I got the ring I immediately walked to that vendor in the conclave and sold it. I think it was a level 82 rare ring but less useful then the rings my Blademaster is currently using. Could just have been bad luck, but still. :undecided:
uhm… he gave me a legendary the 2nd time, on 4 characters…
still wondering…
this and the fact I couldn’t sselect the 3 guys i made join solael’s sect for the sacrifice on another solael’s quest