Problem when instantiate other gameobject.

Hi im working in a 2dtile based game and im new in unity.

The question is, i have gameobject Enemy with enemy.cs script also i have the prefab gameobject deathSpell with a spell.cs script.

in the top of Enemy class i have this

 public GameObject deathSpell; //then i drag the deathSpell to here in inspector

Also i have a function in Enemy script to send a spell to player, like this.

 GameObject instance = Instantiate(deathSpell, orgPos, Quaternion.identity) as GameObject;
 deathSpell.GetComponent<Spell>().hitTarget(orgPos, tgPos);
 Destroy(instance, 3f);

So in the function hitTarget inside Spell class i make this

 spellOrg = origemAtk;
 spellDest = target;
 atack = true;

then in update method of SpellClass i check if atack is true then trace a route to player and hit.

The problem is, the variables of the Spell Class are not being reset even after Destroy command. So if i execute this function

 deathSpell.GetComponent<Spell>().hitTarget(orgPos, tgPos);

in the second time not work properly, is looking unity keep script in cache something like this, even if i stop the game and run again.