"Relay" and Graal

[Urahara112]

Unholy Nation has been having a lot of trouble with cheaters using Relay. We can't seem to get rid of them, they continuously come back, and insist on dropping what appears to be bombs that disconnect multiple players in a single level. Modifying attributes they shouldn't be able to, eg. setting a hat to their player, spawning EP or money, and even setting warps.

My question is, what are our options? How can we stop these cheaters from returning? How can we prevent new cheaters from exploiting this?

We've been trying to deal with it for a while now. Working on detection and making changes to prevent these cheaters from coming right back so quickly. But nothing seems to be working thus far.

Advice?