Removing the hitstun was the central point of this hack, since endlessly stunlocking enemies is really easy with most weapons and one of the things driving the lack of difficulty/undermining the enemy level boosts in Nightmare and No Future mode.
The only other changes I made here that I ended up agreeing with were increasing enemy walk speed and slowing the player's movement speed down, and I don't think those really matter much if hitstun's disabled.
The attack multiplier system I tried to come up with did not work how I intended it to.
If you want a harder version of LoM, try the Japanese version -- the level scaling was changed/bugged? in the US release so all of the enemies are underleveled, as far as I can tell. (The US version also introduced a number of other bugs, most of which don't really seem to be documented, none of which I have any idea how to address). ((Also, since the enemies aren't underleveled in the Japanese version, they do significantly-more-enough damage that abusing stunlock is a lot less safe when you're dealing with a group)).
The asm files aren't really well structured -- I was compiling those separately and then manually reinserting them into the decompressed data? program? files using a hex editor.
Also not sure if you're the person that PM'd me -- the notification email I got isn't showing me that for some reason >:T -- but the only special tool I used was https://www.romhacking.net/utilities/920/