Dante entered the SPARTAN-III program, developed by Colonel James Ackerson, around 2546 while between the age of 5 and 7 when he, along with other orphans, volunteered to become a SPARTAN-III to avenge his family or home planet after their destruction by the Covenant. Once on Onyx, he and the other Spartan candidates were trained by Senior Chief Petty Officer Mendez; surviving Beta Company SPARTAN-IIIs Lucy-B091 and Tom-B292; and SPARTAN-II, Lieutenant Commander Kurt Ambrose a.k.a. SPARTAN-051. He was in Team Saber, one of the leading squads in the Gamma generation of Spartan III's.
It was said that he had "near magical abilities" when it came to explosives. He always knew when they would explode, and when they would fail, too. Dante was the first casualty of Team Saber due to a combination of plasma fire and Needler rounds to his side while helping Lucy-B091 drag an injured Fred to safety after covering the group's rear as they retreated. Dante fell behind as the group retreated, and caught up just when Kurt-051 noticed his disappearance, limping and holding his side. After stating "Sir, I think I got nicked", Dante collapsed and died.
- When Kurt checked his body he realized that not only had a plasma bolt grazed Dante's left side but also half a dozen Needler shards had lodged and detonated under his arm and across his chest, leaving his ribs clearly visible.
- Dante himself was not actually killed by a large explosion due to needler fire but from several needler shards detonating individually sending micro-shrapnel through his body. He also suffered from several serious plasma burns.