What is it with isekai's and the transferees suddenly loosing their moral compass after being summoned.
I get its another world and all that but to suddenly go from 10+ years of killing i bad, to being summoned and suddenly fine with killing a classmate like it's just another Sunday.
When it comes to Anime, I will usually drop it if it involves unbelievably horrible CG and they cut out the meat and potatoes that was in the manga just so they can fit 12 episodes in.
For manga, it usually just takes a slow story build up.