I believe many of the WK users watch at least one anime VOST and probably remember a few buzz words from them. In line with this old thread https://community.wanikani.com/t/manga-anime-mnemonics/10593, I think WaniKani could harness their power by incorporating them into a kind of “alternative” mnemonic.
A good example of this I can come up with are the 電 and 虫 kanji, which could use the fact that in the One Piece world it’s very common to refer to the “でん-でん-むし”, snails (I think technically not insects but non biologists won’t care too much ) that act as telephones. If one already remembers 虫 means insect, it should be straightforward to remember むし if WK could bind the thought of an insect to these snail-phones. The same would go for 電.
This feature could be implemented as a tab named by the Anime. So for example in the page for both kanji there could be a small tab in the Reading Mnemonic section called “One Piece” that shows this match.
The same could be done with Meaning mnemonics. For example, 正義 which means “Justice” it’s also frequent in the OP universe as it’s the word stamped behind Navy’s admirals coat, and OP fans know it says Justice regardless of whether they learn Japanese or not.
Hope you find it useful!