[Need Help] 1 Hit Kill Heart Damage and Less Enemy Damage

I'm making a ROM Hack of A Link to the Past based on Angry Video Game Nerd by making the game impossible to beat.

I need help with Hex Editing.

Where can I change the code from Normal Heart Damage to 1 Hit Kill Heart Damage?
(1 Hit and you're dead)

Where can I change the code to give the enemies less damage?

I'm using Headerless US ROM.

Open the rom in a hex editor, press ctrl+g, type 0x380cf.
At this place you should see a F0, change that to 80 and you should be killed with one hit

Thank you!

But, what about change the code to give the enemies (even Bosses) less damage to make the game even more harder?

There you need to ask SePH or Puzz

SePH Puzzledude Do you know how to change the code to give enemies and bosses less damage? (hard to kill an enemy)

Maybe this is what you are looking for?
https://www.zeldix.net/t1699-advanced-damage-editor

But I do not know whether bosses are there as well.

Maybe also this?
https://www.zeldix.net/t723-hyrule-add-ons

SePH Puzzledude Do you know how to change the code to give enemies and bosses less damage? (hard to kill an enemy)

Yes. This is actually called enemy HP or enemy health and you obviously want to increase their HP, so that they are more difficult to defeat.

There is no list done for this. I do this with Hyrule Add ons. This program might be difficult to use, since it uses some dlls which need to be registered in the new versions of Windows. You are on your own with using this program, since it includes how you're going to handle exe files on your system. Once you have the program running, you choose a sprite and change their HP setting, then hex compare the initial rom and the edited rom to acquire the actual hex address.

Zarby on the other hand made an even more advanced sprite editor, which can do all the changes without actually knowing the hex addresses, so you can make the changes in the program itself. There's also a third program on sprite damage editing made by superskuj.

I personally edited the HP of the Armos Knights boss, as you can see in Goddess of Wisdom hack, you need to fire 8 arrows into one to be defeated, not 3. I could not edit the red one though, which still remains 3 hits with arrows for some reason. I forgot the address though.

Also note: some values are limited and you will Not be able to increase the HP of those sprites indefinitely, since they will have a limit. Some are at max and can not be changed without glitches, like Ganon, who's value is already FF. So no bigger changes are possible, since that needs ASM. You can see what Euclid did in Parallel Worlds, however this is much more that just some byte changes.

isn't add-ons no longer necessary thanks to superskuj's editor which has more features?