I'm looking for brain wallet implementations like warp wallet. Are there other brain wallet implementations that involve stressing the computer in order to generate a bitcoin address?
You can use any algorithm you like to generate a 256-bit hash.
For example, you can go to this site to generate a PBKDF2 hash, using as many iterations as you like: https://www.freecodeformat.com/pbkdf2.php
From there, you can copy the hexadecimal result to the bitaddress.org site, or use it as entropy data at the Ian Coleman BIP39 site, and generate an entire tree of private keys.
Regardless of your key stretching algorithm, you had better be certain you start with an extremely strong brainwallet password, and be able to readily remember it. My shortest brainwallet password is over 40 characters long. My longest is 101 characters long. None of my passwords resemble book excerpts, song lyrics, limericks, or common idioms, in any language. Yes, they are all committed to memory.