You can technically implement “client-sided” anti-cheats (as in, anti-cheats running in one client to detect another client’s cheats), although that is trickier than server-sided anti-cheats for sure (for instance, aim and movement checks are much easier to implement client-sidedly than lag checks).

Bloody amateur cartoon villains, attempting to do mass mind control…

Server-side anti-cheats, like Polar for Minecraft.

It is a grammar checker.

Use Harper, instead. It runs locally, and gives nearly instant results.