This is just a simple suggestion.
Currently the orbs surrounding vanduke during fighting his body, provide no extra difficulty to the party at all, the only thing they manage to do is get pure swordsmen kicked from the party, therefore forcing players to equip guns or GTFO, so my suggestion is to either remove the orbs or add MORE of them to force players to water the orbs before shooting at vanaduke, and not forcing a single strategy when fighting him.
"forcing" like it's the only one. orbs don't just stand there, they block bullets. bullets like blitz's. bullets like vials. for an optimal fight, you should water the orbs always. too bad the time it takes to water is better spent blitzing cause it's more efficent that way.
in short, it's not vana. it's blitz.