I have two ideas #1 hire a 100b ally and drop or reset, his choice. I did that once and they took the 10b ally. #2 another idea is for him to write an official appology on your wall. this is a humiliating cf thrm that was implemented against me a few months ago.
Make him buy 50b worth of allies. He buys your ally, you buy another, he buys, etc etc. You'll make like only 3b but the point is to hurt him a little really. Or if he has a few hundred pots, make him sell them all.
If you want the best advice I can give, just stop all hits if they seem like a relatively decent person or a good fighter. Have a chat and become mates. Similarly to snr, I reckon a new friend who knows how to fight is better than an old enemy who might come back for revenge one day. 80% of my friends on kaw are people who I have either fought or argued with, and we've sorted out our **** and become friends. They can also help with farming issues later on if you aren't willing to fight your own battles, which we can see is probably the case due to this thread.
Their CP is interesting.. Get a group a friends and strip? Seems like they are looking for a fight.. Gotta be careful who ya clan bang