a good voidwalker will see anyone in the bubble making a bolt for survival, and adjust their aim accordingly to maximise kills. a better voidwalker will be ready to dispatch any survivors by using the momentum maintained by casting a ova bomb to carry him into cover to withstand a counter offensive. thats part of why most void walkers have a habit of jumping before casting it, to take advantage of the momentum. along with giving us greater distance with a non-lance nova bomb, and a better veiw of where the (hopeful)crowd of targets is going to let us make last second aim adjustments. unfortunately that habit tends to bite us in the ass when casting into doorways :P