This looks interesting - Introducing easywallet: a simple and secure brainwallet
The purpose is to make it easier to memorize a seed phrase, temporarily or in case you need to, for instance, cross borders without any evidence of bitcoin.
A portable wallet that you don't want to store on any physical media, but only in your memory, and only for a short amount of time. Example: You need to flee your home country with your life savings, and you don't want your private keys to be on your computer or any hardware wallets on your person. You can commit your easywallet to memory, transfer your life savings into the easywallet for temporary storage, then once you are in a safe place you can transfer the funds from the easywallet into a more secure traditional wallet.
Basically, what you have is a publicly known repeated 12 word BIP39 seed phrase (for example, action action action action action action action action action action action action), and then a private, memorized 7 word passphrase.
So, you're not getting ANY entropy from your seed phrase, you're getting it all from the 7 word passphrase.
The theory is that 7 words (properly random words from the BIP 39 word list, though the OP uses the Electrum word list) give enough entropy for temporary use. A quote:
This will give us a passphrase with 90 bits of entropy. Coldbit estimates a passphrase of this strength will take an "infinite" amount of time to crack even on the most advanced passphrase cracking computers that could theoretically be invented.
I'm working on new exercises for my book MORE Bitcoin, Hand-On! (my previous book Bitcoin, Hand-On! is available here - https://www.amazon.com/dp/B0F4SZSCH8).
And I'm thinking of making this one of the exercises. With the appropriate caveats, I think it would be great to learn more about entropy, and about some of the options that are out there.