What do you mean by asking vengeance? That is no prayer Christ has taught you. He commands you to love your enemies, to bless them that curse you, to do good to them that hate you, and to pray for them which despitefully use you and persecute you. To call down destruction upon another soul is to forget the mercy you yourself have received. You are a sinner saved by grace alone, and will you now cry out for wrath upon a fellow sinner? Cast that bitter thought from you at once.
And why do you speak of a guardian angel as if you would command the heavenly host? It is God himself who is your refuge and your fortress. The angel of the Lord encamps round about them that fear him, but it is not for you to summon angels as though by some private right. Their service belongs to God alone, and he dispatches them according to his own will, not the dictates of your fears. The promise is sure: He shall give his angels charge over you, but that charge is given by him, not demanded by you. The angelic protection you seek is real, but it is not appointed in the way of demanding vengeance, nor in walking after error, nor in claiming powers God has not given. Walk in obedience to divine precepts, do what God tells you, as God tells you, and because God tells you, and then no hurt can come to you.
What I see in your request is a soul in great distress, feeling hemmed in by enemies, and that I understand. But the answer is not to cry for angels to scatter foes; the answer is to hide yourself under the shadow of the Almighty. He shall cover you with his feathers, and under his wings shall you trust. This protection is perpetual and personal. You are to rest in God, not in a supposed angelic army at your back. The soul that dwells in the secret place of the Most High abides under the shadow of the Almighty, and there he finds perfect safety, not by fighting his own battles in prayer, but by leaving all vengeance to the Lord. The Lord is your keeper; the Lord is your shade upon your right hand.
Cast yourself, then, upon the divine faithfulness. Our Lord Jesus Christ has told you that the very hairs of your head are numbered, and that not a sparrow falls to the ground apart from the Father. Will you not trust him to order all things for you? If you are in Christ, then not a single foe can touch you apart from his permission, and whatever he permits, he will overrule for your eternal good. This savors not of human merit, but of divine mercy. The Lord says, “Because he has set his love upon me, therefore will I deliver him: I will set him on high, because he has known my name.” Does that describe you? Do you love him? Have you believed on his Son, Jesus Christ, for the forgiveness of your sins? Then he says, “He shall call upon me, and I will answer him: I will be with him in trouble; I will deliver him, and honour him.” There is your safety, not in commanding angels, but in calling upon your God through the one mediator, Jesus Christ, who alone is your peace.