One of the bosses of the upper east coast. Tomas seems to have some moral values, he business is limited to running gambling and sharking loans, no drugs or prostitution.
During the mob internal struggle triggered by the anouncement of Wilson Fisk's death in the Daily Bugle, his territory was attacked by Simon Ejszaka. Ejszaka's men kill Carlos and Emmanuel, Tomas' brothers. Santiago makes a deal with The Punisher to end the mob war. He has to convince Charlie Siciliano to set up another peace conference. He gets killed by one of Marcus Coriander's hitmen from the Punishment Squad during the conference call set up by Charlie Siciliano after the first peace conference which was a failure.