Thank you Conifold for mentioning this in the comments.
Appeal to self-authority (self-expertise)
https://rationalwiki.org/wiki/Ipse_dixit
Self-superiority bias
https://en.wikipedia.org/wiki/Illusory_superiority
Here's the backstory. Occasionally, I've heard people try to appeal to a great many books they've read on the matter at an argument. For instance, this anti-evolution zealot professed this. When I examined which books, they unveiled a list of texts (mostly without credible authors) which only fit their preconceived beliefs.
Recently, there has been a different but exceptionally irritating person. It was clear they didn't know what they were talking about related to ethics. But I try to keep and open mind, give them the benefit of the doubt. At first glance they seem to fit, 'Jack of all trades, master of none' with areas of knowledge.
So when the voice chat room subject changed to biology or evolutionary biology, they also professed to be well self-educated on that matter too. I do not know about this subject. However, they fit a pattern; they use very slimy methods to appear knowledgeable on whatever topic comes up:
- "I've studied this for the past 15 years." (I.e., Google.)
This would be fine with me. Although, I've noticed they use this statement to try to weasel their way into a position of credibility for any subject that comes up. When someone entered the room who actually had a wide breath of knowledge related to evolution, they simply shut their nonsense down.
- Describes very specific subject matter with technical language, even though it doesn't relate to the topic at hand.
For this is simple: non sequitur.