>>/2373/
Also not a SE, my background is more in Biz/Data. But I assumed that the initial DevilxEngine, was hosted on another server which provided a PoW puzzle for the browser to handle prob with some criteria on the browser and if it was completed then you were given a cookie, which is why JS was required. After that you were redirected to the main server.
Then I think this cookie resat every hour by the end of it which is why posts made around hh:55-59 were not accepted. Or something happened with the servers during this threshold, to avoid DDOS attacks.
Then the engine also worked with posts too. So there was probably some regex or some rules to determine if a post was applicable or not.