If you liked
Ansatsu Kyoushitsu
|
...then you might like
Yakusoku no Neverland
|
If you like the whole "I've outsmarted you!", "But I've outsmarted you!", "And I've outsmarted you!" etc. aspect, both of these anime contain plenty of that in them, as well as the dangerous guardian (Koro-sensei/Mama) facet.