Fast forward a few years, Leo is now about 21-22. He's already taken on Vex (Black Garden and VoG) and helped the Reef (HoW stuff). His father died mysteriously. He's now a top notch Guardian, hunting Kings while doing normal Guardian stuff. He's got his own fireteam which includes his Awoken Titan girlfriend. Soon, however, Oryx arrived. After all that stuff with his arrival he speaks to Leo thru an Echo saying that he killed his father as revenge for Crota. Now Leo is preparing himself to avenge his father.