What's really concerning - and most indicative of this conman's insiduos and cunning nature - is how he manipulates Diego to burn bridges and isolate him from his professional network and from people who know and care for Diego, and would/is no doubt be critical of this Fabio guy.
He is essentially, isolating Diego more and more, so that his and Diego's relationship become even more 'meshed' and symbiotic, making Diego more and more dependent on himself.