Two requests....

[Roland_Deschain]

ONE: A magic system that runs off HP as opposed to MP.
TWO: A "protect" spell that lets Character A take a percentage of Character B's damage, a la FF4.

Thanks in advance.

[Prpl_Mage]

DO you need this or are you going to make it?

Anyone, the first thingy more or less requires one thing.'
A battle event that are triggered when you use that certain skill.
When it's used- decrease the heroes' HP by the certain ammount.

The only problem is that you'd be able to use it even if your life was down at 1 and it costs 40. Unless you make it possible to die from the reduction.
This is where Rpgm fail again and c++ is better.

Anyway, you could simply make the actual damage and skill as an event and not an actual skill.
Add a conditional branch to see if the hero got enough health.
Check the target of course.
Do the calculations for damage.
Decrease monster hp.
Add the health recoil.
Turn the skill's switch off.

That should work.

Or, you could just set the MP and HP equal to each other and have a parallel event that sets the value of HP equal to MP. So if the hero got 400hp and 400mp and use the bloodsport spell.
He loses 50mana.
And he only got 350mana then, so the health is set to 350 as well.

[Roland_Deschain]

That works, and yeah it needs to kill the person. Thanks. >_> And I'm betting part two is impossible?

[Prpl_Mage]

Well, not quite. But that's another thing that would be more effective in a real programming language.

Here is just a theory.
Make a skill that adds the status prob "guarded" or whatever, the status doubles defense.
Add a battle event so that a switch is turned on.
Then just give the same amount of damage the guarded character took to the one who guarded him.