Auto revive at battle's end

Hello there guys.
So, basicaly, i want that in my game, if an actor goes KO during a battle, at the end of the fight, he will return back to life with 1HP.
How can i do that?
If it's possible without plug-in that will be better

You could script that at the end of the battle, you revive all allies, and set their HP to 1.
It's possible with eventing alone, so no plugins needed.

Not sure wether you can set an actors HP to a set amount, but you can allocate a variable to his max health.
Then, when you revive an actor, revive him to full HP, and reduce his HP by said variable - 1.

And i need to do that in the event page of EVERY battle?

That's one way. Another similar way is to run a common event at the end of every battle. And have your common event handle this.

Much simpler: go to your "K.O." state (probably state #1) and tick "Remove at Battle End".

What if the actor will loose the state but stay at 0HP?

Is there a meaningful difference between reviving at 0HP and reviving at 1HP? Both imply "knocked out by taking any damage at all".

Technically impossible
there is a part of the engine that automatically connects HP and state#1 - if the state #1 is removed then you automatically get 1 HP because on the other hand, you automatically get state #1 if an actors HP gets to 0 at any time.

so placing the autoremoval after battle on the death state is the simplest way to do this, but this only works due to the special coding for HP and state #1 that is included in the engine.