From being a cruel voluptuary and assassin, he was changed to a merciful ruler who could not bear to inflict capital punishment.

He was faithful to his Greek wife Anna.

On the spot where he had once erected Perun, and where the two Scandinavians were martyred at his command, he built the church of St.Basil; and he is now remembered only as the saint who Christianized pagan Russia, and revered as the "Beautiful Sun of Kief." So the two most important events considered thus far in the history of this land have been, first, its military conquest from the North, and second, its ecclesiastical conquest from the South.

If the first helped it to become a nation, the second determined the character which that nationality should assume.
To explain one fact by another and unfamiliar and uncomprehended fact is one of the confusing methods of history! In order to know why the adoption of the form of religion known as the Greek Church so powerfully influenced Russian development, one must understand what that faith was and is, and the source of the antagonisms which divided the two great branches of the Church of Christ--the Greek and the Latin.
The cause underlying all others is _racial_.

It is explained in their names.