Reversing HP gauge

So I'm trying to make the HP gauge into a fatigue gauge where you start at 0/30 fatigue and if you reach 30/30 fatigue, it'd be game over like 0 HP. So, is there a good way to approach this, maybe by using the TP gauge instead? 

http://www.rpgmakervxace.net/topic/12954-empty-tp-upon-death/

This isn't the original idea you had in mind as it involves the tp gauge. I would imagine in the troop event page you could set it for allies to lose 1 tp every round.

At least this sets you up for an ally to die when tp = 0

Maybe you can use the MP gauge as the fatigue instead? HP does not go below 1 without causing a knockout.

The following example increases MP (fatigue) by one every ten seconds. You can create events to increase your MP as well.

When the player's MP reaches 30, the conditional branch will trigger your gameover sequence.

1) Create an event that will autorun on game start.

    - Create a switch "Start". Change MP "Entire Party" "Decrease" "30".

    - Create a New Event Page and select Switch "Start" is ON under Conditions. Leave the page blank.

2) Create a common event with parallel process trigger on "Start" Switch.

     - Add wait 600 frames. (this equals 10 second).

     - Add a Script call "$game_party.members[0].mp += 1" without the inverted commas; or        (this will increase the first party member's MP by one)

     - Add a Script call "$game_actors[1].mp += 1" without the inverted commas          (this will increase the MP of the first actor in your actor database)

     - Create a Conditional Branch to check the following Script "$game_party.members[0].mp == 30" without the inverted commas. Set handling off.

     - Directly under that, place your gameover sequence.

You can change the labels and numbers to suit your game. Maximum wait frames is 999 each (around 16.6 seconds). You can make multiple instances of this command. If you need a longer time frame, you can utilize variables.

Hope this helps!