Ok, in Haypi, there is no one that can really help other than learn some defensive techniques yourself.
So upgrade your defenses, (level 9+ turrets if you have them, otherwise all traps). Upgrade your cranny, upgrade your Scouting tech.
Scout him and all his oasis, you need to be active yourself, if you see him online all the same then you probably in the same timezone as him, you need to learn his online pattern carefully, attack his oasis when you believe he is offline, target crop oasis specifically.
Also constantly scout him, scout him whenever you can, find out whom are the active high level attackers in the server and if you see his army sitting out for a while send the coords to all those big attackers (make sure they're not in the same alliance as him

)
Steal his oasis and forts whenever you get the opportunity, make sure you scout them carefully so that you don't get trapped, attack with cavs so he can't respond as quickly, make sure you don't attack with too big of an army.
If all that doesn't work, then consider moving your cities further away, but you can always keep a low level city near him to annoy him
