This is going to be a long story. Part of it will be in Spanish, so I hope that's not an issue.

I first came across this user on a wiki I run alongside a fellow user, Wiki Lovecraft (in Spanish). He kept on creating barebone articles, something that felt rather suspicious. I blocked the user, who then used the anon IP 188.163.47.251, when he insulted me after a string of deleted articles: https://hplovecraft.fandom.com/es/wiki/Xiclotl?diff=18407&oldid=18406 (in Spanish).

In the meantime, I found out that he had been plagiarising contents through different wikis. He always acts the same way. First, the user creates a barebones article on Wiki A. Then, he waits for the article to be fleshed out by Wiki A's editors. Once it's done, the information is copypasted on Wiki B. When he's exposed, he retaliates by insulting everyone involved on the block and asking for his account and anons' to be unblocked.
I told my colleagues on the Lovecraft Wiki in English about this user's behaviour, stressing how problematic dealing with a translation of a translation was: https://lovecraft.fandom.com/wiki/Talk:Lithard

The user came to me after the block, and he asked me to stop deleting his contents, to which I replied in kind: https://hplovecraft.fandom.com/es/wiki/Muro:AzureKesil?threadId=4400000000000035185 (in Spanish). This user was blocked twice since then, as he refused to comply with the rules. Still, he came back as 188.163.110.107, That's why I used a ranged block.

Recently, he came back to Wiki Lovecraft as Doom2018, acting as usual. Knowing he seemed to be related to the anon accounts, I set a honeypot of sorts and asked the Spanish Community Central for a checkuser request. This honeypot came in the shape of information coming from a relatively unofficial source in English, ensuring the names were adapted to Spanish. The user fell for the honeypot hook, line and sinker, and promptly added the information on the Lovecraft wiki in English.
*Article in Spanish, with my fellow user adding categories after my final edit for that time being: https://hplovecraft.fandom.com/es/wiki/Eihort?diff=next&oldid=19720
*Article in English, with 188.163.110.107 copying everything and overwriting previous contents: https://lovecraft.fandom.com/wiki/Eihort?diff=35899&oldid=35378

As for the checkuser, I was told that Doom2018 was indeed a part of the ranged block.
At this point, I told my colleagues about what had been going on, and they were okay with yours truly adding a template on fully plagiarised articles. Furthermore, they were okay with having existing articles revert to previous versions.
* Link to the conversation: https://lovecraft.fandom.com/wiki/Message_Wall:RingoRoadagain?threadId=4400000000000028133
*Link to the checkuser request (in Spanish): https://comunidad.fandom.com/wiki/Muro:SacredOwl?threadId=4400000000000151589

The user kept on proceeding as usual, and was blocked after insulting users for taking measures against his edits: https://lovecraft.fandom.com/wiki/Special:Log?page=User%3A188.163.110.107&type=block
After this block, Doom2018 began retaliating against Lovecraft Wiki users with his account as well as using the anon IP 188.163.110.107. I deleted one of his comments, but he posted again. I noticed that he tried to edit my Community Central profile, successfully doing it as Doom2018.
* https://community.fandom.com/wiki/Special:AbuseLog?wpSearchUser=188.163.110.107 Abuse log showing how he tried to edit my profile with the anon IP
*https://community.fandom.com/wiki/User:AzureKesil?diff=3429729&oldid=1827467 Vandalising my profile as Doom2018
*https://community.fandom.com/wiki/Message_Wall:AzureKesil?threadId=4400000000003149136 Pestering me as an anon IP
*https://community.fandom.com/wiki/Message_Wall:Zombienomicon?threadId=4400000000003146385 Pestering user Zombienomicon as an anon IP
* https://community.fandom.com/wiki/Message_Wall:RingoRoadagain?threadId=4400000000003132221 Pestering Lovecraft Wiki staff RingoRoadagain as both Doom2018 and an anon IP, especially after his attempt at adopting Lovecraft Wiki.

This is not the first time he behaves in such way when asked about his editing style and sockpuppeting, yet he acts as the anon IPs (and probably some other non-anon accounts) had nothing to do with him. Here are some examples:
*https://community.fandom.com/wiki/Thread:Love_Robin/@comment-1682045-20200417034043/@comment-35934438-20200418093201
*https://community.fandom.com/wiki/Message_Wall:AustinDR?threadId=4400000000002592314
*https://community.fandom.com/wiki/Thread:B1bl1kal/@comment-45217175-20200802151901/@comment-188.163.47.251-20200830164709
*https://community.fandom.com/wiki/Message_Wall:MisterWoodhouse?threadId=4400000000002334235
*https://community.fandom.com/wiki/Message_Wall:Sannse?threadId=4400000000002389433
*https://extraterrestrials.fandom.com/wiki/Message_Wall:Robergestudios?threadId=4400000000000026030#4400000000000061956
*https://syfychannel.fandom.com/wiki/Thread:Griffguy26/@comment-35934438-20200318101456
*https://syfychannel.fandom.com/wiki/Message_Wall:B1bl1kal?threadId=4400000000000024207
*https://syfychannel.fandom.com/wiki/Message_Wall:Chakor_Channing?threadId=4400000000000024214 (this one is very reminiscent of his attempts at insulting me).
*https://lovecraft.fandom.com/wiki/Message_Wall:FANDOMbot?threadId=4400000000000001210 (ranting to a bot here + sockpuppeting)