He is a member of the Infinity Trio, being older than Lucciano, and younger then Jose. Placido is shown to be impatient and will do anything to remove any obstacles that get in his way, and as such seems to not get along with Jose. He also has a habit of threatening Jeager with his sword when he fails, or messes up. He seemingly holds a grudge against Yusei after the latter defeats Ghost. It would appear he was in league with Rex, as he stated the Crimson Dragon ruined things for him, and decides to prevent it from interfering with their plans. Placido along with Jose and Luciano appear at the crash site of Wisel's tablet. When Jeager questions their reason for being at a forbidden location, he threatens Jeager by drawing his sword. Luciano says they are he's new bosses. Jeager then immediately recognizes them as being from Yliaster. He then orders him to take the "card" back to Sector Security while deciding to test its power.

(Source: yugioh wikia)