Mandroid M-99 is working as Mandark's most trusted droid. He knows that after Spawns take DNA samples from heroes and fusing them with the dangerous green Fusion Matter the fusion is created with DNA and Fusion matter. The Fusion creates a Nano after it is destroyed. Once the Fusion is destroyed it separates into two pieces of Fusion Matter thus creating a nano. Only Dexter, Ben, Mandark, Gwen, Edd, Numbuh 4, Professor Utonium and Mandroid M-99 know this.