He probably cheat's using bots, Evony probably caught him and they reset him, read the EULA they don't have to explain it, you bot get caught lose your acc and yes it does happen, most of the top people playing Evony us bots and if they say they don't! you can probably be almost 99.9% right to say their lying.

Lots lose accounts for this reason, but only Evony knows who they are! and they won't tell you! :P