i have small idea, maybe not so new i dont know, i just came back round 61 and did not check the entire forum here
maybe you can change the captchas a little bit, let me explain because my english is not that good
1st the hunter/atacker enter raves
2nd the hunter/atacker must set assault
3rd this is your code writing job developer, when the single assault or the gangassault is planed, your victim cannot make anymore plastic or dying for this movement,(of course can be dead by other user and if dead should be only shown that user is in hospital , but assault have not to disapear) and should be posible to kill after entering the captchas, only the assault must disapear when the atacker enter 3 times false captcha text.
4th after a correct captcha the assault must be performed
hope i explained me good
this should avoid bot hunters little bit