While working on Memento Mori with his brother Milo, Dario met several members of TeamTNT, and eventually joined the group. He created two levels, and co-authored one more, for TNT: Evilution, then designed half of the levels in The Plutonia Experiment. He has not worked with TeamTNT since Final Doom was published. More recently, Dario has released both solo and deathmatch Quake maps, and is currently employed by Valve Software (including contributions to Half-Life, Team Fortress Classic, Half-Life 2 and Left 4 Dead). He was most recently listed in the credits for Portal 2.