Angels don’t have “enns.” I don’t know why people keep thinking they do.
An enn is a specific type of mantra in the demonic language from the practice of demonolatry. They apply only to demons, nothing else.
Angels have psalms.
For Micheal, try Psalm 91, known as the Soldier’s Psalm.
Or Psalm 113, for his aspect as the Archangel of the Sun:
Praise ye the Lord. Praise, O ye servants of the Lord, praise the name of the Lord. Blessed be the name of the Lord from this time forth and for evermore.From the rising of the sun unto the going down of the same the Lord’s name is to be praised.The Lord is high above all nations, and his glory above the heavens.Who is like unto the Lord our God, who dwelleth on high,Who humbleth himself to behold the things that are in heaven, and in the earth! He raiseth up the poor out of the dust, and lifteth the needy out of the dunghill; That he may set him with princes, even with the princes of his people. He maketh the barren woman to keep house, and to be a joyful mother of children. Praise ye the Lord.