put them to verge of death and let's see in later chapters if those 2 lolis actually have brain issues or not. Hopefully they grow new brain cells and stop doing their drama inducing activity after this.
Tbh, it's actually okay for them to die imo and make the MC develops some kind of trauma, there're already mysteries ongoing like his reason for gettin isekaied , mysteries of twins, and mysteries of goddess that will compel him to move the story, then later, author can just reintroduce concept of twins by letting the mc to meet another victimized twins, but this time he will have good enough trauma for extra drama.