Restriction order after a fight have finished

[ISTK]

So my friend had a fight at lvl 9 against a monster so I used a curse so he lose a lvl and won the fight. Now he is lvl 9. Now after the fight he wants to use the restriction order and all cards that have been used must lose its effect, would he won this way as the card would never have made him lose the lvl?

After that another friend used monsters are busy and he used the restriction order again, but we can't decide if monsters are busy is strictly against him or affecting him negatively as the card won't let him fight the monsters but will allow him trade cards for benefits

[Brf]

Restraining Order does not work well with cards that had an immediate effect.
It only returns the cards to the player's hand but does not remove the immediate effect the card had when it was played.