What is correct way to proceed after a battle?

I am not sure sure about what to do after, do it need to be reshuffle with used cards or

or just leave it be for next battle.

And/or if cards in the deck is totally empty what have to be done.

reshuffle all cards in the deck or all cards except the last used cards

i want to know so much.

You shuffle all the tides of battle cards before each battle, so all are available in the draw pool for each battle.