Board Thread:Questions and Answers Forum/@comment-209.6.64.184-20141204122701/@comment-25250760-20141204151009

You must have killed something, then. Nova Bomb being the Voidwalker super ability is how you would generate the orbs. There are modifiers that likely would have helped, such as Shatter. With the Shatter modifier, you could damage enemies to the point they're almost dead, then the projectiles would finish them off. That still counts as a super kill, thus generating orbs.

The same can happen with a Titan's Fist of Havoc super ability and the Aftermath modifier. The Aftermath modifier leaves a pulsing effect at the point of impact, which can still kill an enemy if they walk into the effect, thus generating orbs well after using the super ability.