Now there are human armies advancing, and Du You's mission is completed. After all, doing other things in this world would not yield any more rewards due to the special nature of the power-up mission.
As for slaughtering, Du You had reached the second tier, so to kill first-tier creatures would be too costly for little gain. Therefore, Du You didn't bother competing with other soldiers for merit.
At the most, Du You would cast a spell when soldiers were in danger to offer aid, while also testing the increased power of his spells. As for the summoned creatures, Du You had already recalled them all.
Using these low-level creatures for experimentation would not yield accurate metrics of their true strength.
Other soldiers offered no opinions about Du You's actions. At most, they simply admired him.