help for returning a character to his normal form

[Shoki 0]

Hi , I begin on RPG maker and I've got a problem with a thing : 
I create a special skill class  called ultimates. One of this spell is a transformation. So I put buffs ( using base option of rpg maker mv )  and create a common event for some "cinematic" things ( I remove things like music from the code here because it's not the problem) . But when I try the skill,  the character manage to transform but at the end  of the battle he is still in his upgraded form. I want an automatic for this transformation and not doing all event in Troops for returning the  hero to normal from. Can you help me ? 

 

Hero appearance : Héros,ssj(0),hero(0),ssj

if: Script : $gameTroop.isAllDead() 

   Hero appearance : Héros,hero(0),hero(0),hero
  

end

 

[Lord Vectra 414]

Make a parallel process common event that changes him back.