https://www.pcgamer.com/meet-maestro-the-second-italian-operator-coming-to-rainbow-six-siege/

Ubisoft has revealed a new teaser and background information for Maestro, the second Italian operator coming to Rainbow Six Siege in Operation Para Bellum. The oldest of eight children, Maestro—real name Adriano Martello—joined the Carabinieri at 18 and earned a spot in the 1st Paratrooper Regiment, then moved to the Gruppo di Intervento Speciale (G.I.S.) and took part in joint operations in Iraq. 

Following that experience, he retired and went into business for himself, training special forces troops and PMC mercenaries. He eventually decided to re-enlist, first to help train a Tuscania unit to a Tier 2 classification, and then as a member of the Rainbow team. None of which tells us what he's going to do when the bullets start flying, although the intro hints at it.