Shatras's solo return to the Naga tribe ahead of the others was at John's request.
John was well aware that the series of events that had transpired had caused some friction between himself and the Naga Queen.
It was crucial for him to first ensure that the Naga Queen did not harbor significant hostility towards him.
If the Naga Queen held substantial animosity against John, he would need to consider alternative strategies.
John already had some plans in mind for how to target the Dark Realm next.
During his battles with the two Devils from the Dark Faction, he felt the imperative need to strike back against the Dark Faction.
After defeating the two Devils, John spent the duration of his fight with Darklord contemplating how he could most effectively weaken the Dark Faction.
Upon concluding all his battles, John finally devised an excellent course of action.