If Sol Invictus is a fitting title for Our Lord, Jesus Christ, Second Person of the Holy Trinity then there should be at least one record of saints or approved prayers by the One Holy Catholic and Apostolic Church which invokes Him under that title.
Is anyone here arguing for the use of these titles in the use of public litanies, or the like?
There is no scandal in Vigano's use of the title in a speech.
Adding to that, I have no doubt it is lawful to come up with litanies for private use.
Sol Gloriae, grant us a crown of glory in Heaven.
Sol Resurrectionis, grant us incorruptibility.
Sol Intelligentiae, grant us wisdom.
Sol Castitatis et Iustitiae, grant us purity of heart, so that we may see the face of God.
Sol animarum nostrarum, have mercy on us!
Ardenti Sol Iudicii, spare us o Lord!
Sol Invictus, grant us the grace of final perseverance!