well if you set the health of it to a negative amount it won't display its health bar
(use shift so you can actually set it to a negative amount)
That will make the unit becomes invincible and won't die.
And it hides the
HP/MP Indicator under the unit's portrait, not the health bar in-game.
1. Open Object Editor.
2. Go to Units Tab.
3. Select any unit (the unit to be hided its health bar).
4.
Change the Art - Selection Scale to 0.00.
5. You will notice that the minimum values it can go, is 0.10, press Cancel.
6. Hold Shift, then double-click the field, again.
7. Change the
Art - Selection Scale to -0.10
Here's a test map if you can't understand those instructions.
EDIT:
By changing it to 0.00, it will bug out the position of Player's Name and Hero Level.
Just make sure you set to -0.10.
-0.01 is also acceptable.
Just don't 0.00.