(a) Harassment by telecommunication device is the use of:
(1) A telecommunications device to:
(A) Knowingly make or transmit any comment, request, suggestion, proposal, image or text which is obscene, lewd, lascivious or indecent;
(B) make or transmit a call, whether or not conversation ensues, with intent to abuse, threaten or harass any person at the receiving end;
(C) make or transmit any comment, request, suggestion, proposal, image or text with intent to abuse, threaten or harass any person at the receiving end;
(D) make or cause a telecommunications device to repeatedly ring or activate with intent to harass any person at the receiving end;
(E) knowingly play any recording on a telephone, except recordings such as weather information or sports information when the number thereof is dialed, unless the person or group playing the recording shall be identified and state that it is a recording; or
(F) knowingly permit any telecommunications device under one's control to be used in violation of this paragraph.
(2) Telefacsimile communication to send or transmit such communication to a court in the state of Kansas for a use other than court business, with no requirement of culpable mental state.
(b) Harassment by telecommunication device is a class A nonperson misdemeanor.
Kan. Stat. Ann. § 21-6206 (West)
Here's a /qa/ thread of him admitting that he's the one behind the continual harassment. Obviously 4chan isn't going to release IP information without a warrant or subpoena, that will require an active investigation.
https://desuarchive.org/qa/thread/1261832/#q1262538_3. I'm sure there's more I could find if I took more than two minutes to search
Admins, you have his IP's still. He's given you consent to have access to that. Please take action.