Michael (Hebrew pronunciation: [mixa'?el]; Hebrew: miykael, translit. Mikha'el, lit. 'Who is like God?'; Greek: Mikhael, translit.
Catholicism
Catholics often refer to Michael as "Holy Michael, the Archangel" or "Saint Michael", a title that does not indicate canonisation. He is generally referred to in Christian litanies as "Saint Michael", as in the Litany of the Saints. In the shortened version of this litany used in the Easter Vigil, he alone of the angels and archangels is mentioned by name, omitting Saint Gabriel and Saint Raphael.  In the Roman Catholic teachings Saint Michael has four main roles or offices. His first role is the leader of the Army of God and the leader of heaven's forces in their triumph over the powers of hell. He is viewed as the angelic model for the virtues of the spiritual warrior, with the conflict against evil at times viewed as the battle within.  The second and third roles of Michael in Catholic teachings deal with death. In his second role, Michael is the angel of death, carrying the souls of all the deceased to heaven. In this role Michael descends at the hour of death, and gives each soul the chance to redeem itself before passing; thus consternating the devil and his minions. Catholic prayers often refer to this role of Michael. In his third role, he weighs souls in his perfectly balanced scales. For this reason, Michael is often depicted holding scales.  In his fourth role, Saint Michael, the special patron of the Chosen People in the Old Testament, is also the guardian of the Church; it was thus not unusual for the angel to be revered by the military orders of knights during the Middle Ages. Thus, the nomenclature of villages around the Bay of Biscay reflects that history. This role also extends to his being the patron saint of a number of cities and countries.  Roman Catholicism includes traditions such as the Prayer to Saint Michael which specifically asks for the faithful to be "defended" by the saint. The Chaplet of Saint Michael consists of nine salutations, one for each choir of angels.

Q: what did he do with catholicism?
A: His first role is the leader of the Army of God and the leader of heaven's forces in their triumph over the powers of hell.
did he have any struggles or conflicts?
In this role Michael descends at the hour of death, and gives each soul the chance to redeem itself before passing; thus consternating the devil and his minions.
In this role Michael descends at the hour of death, and gives each soul the chance to redeem itself before passing; thus consternating the devil and his minions.