[Scripting Question] Putting Eerie Spell into my game

################################################################################
# Puts the target to sleep.
################################################################################
class PokeBattle_Move_[B]003[/B] < PokeBattle_Move
  def pbEffect(attacker,opponent,hitnum=0,alltargets=nil,showanimation=true)
    return super(attacker,opponent,hitnum,alltargets,showanimation) if pbIsDamaging?
    return -1 if pbTypeImmunityByAbility(pbType(@type,attacker,opponent),attacker,opponent)
    if opponent.pbCanSleep?(attacker,true,self)
      pbShowAnimation(@id,attacker,opponent,hitnum,alltargets,showanimation)
      opponent.pbSleep
      return 0
    end
    return -1
  end

  def pbAdditionalEffect(attacker,opponent)
    return if opponent.damagestate.substitute
    if opponent.pbCanSleep?(attacker,false,self)
      opponent.pbSleep
    end
  end

  def pbEffectAfterHit(attacker,opponent,turneffects)
    if isConst?(@id,PBMoves,:RELICSONG)
      if isConst?(attacker.species,PBSpecies,:MELOETTA) &&
         !attacker.effects[PBEffects::Transform] &&
         !(attacker.hasWorkingAbility(:SHEERFORCE) && self.addlEffect>0) &&
         !attacker.fainted?
        attacker.form=(attacker.form+1)%2
        attacker.pbUpdate(true)
        @battle.scene.pbChangePokemon(attacker,attacker.pokemon)
        @battle.pbDisplay(_INTL("{1} transformed!",attacker.pbThis))
        PBDebug.log("[Form changed] #{attacker.pbThis} changed to form #{attacker.form}")
      end
    end
  end
end