For the ABS:
Create your respawn point using "Memorize Position" command.
I would use a Variable in place of the user's HP, subtracting from the Variable each time damage is dealt, rather than the HP. then in a Parallel Process (either in common events, or in a map event) use a Fork Condition stating when HP is less than or equal to 0, Go To Memorized Position, then increase the Variable by 1, giving the Hero 1 HP, or however you want to do it.
You will not be able to show the Hero's true HP in the DMS though. You will need a Menu that shows the Variable's amount rather, since it will be acting as the hero's HP.
That's how I would do it. It would take a little more working with, but there are the basics.
I will take more time and create an entire tutorial when I figure out how to make it flawlessly.