There are many Universal themes at Magi. First, is humbleness, as the couple (who are obviously Victorians) cannot do what the rest of society does when it comes to trying to keep up with the upper crust and be one of them: This couple is doing the exact opposite and understanding their circumstancial position.
Then, there is love, of course, in the shape of sacrifices.
There is also humility- way different than humbleness- which means the capacity of accepting defeat without feeling humilliated.
All these topics are written within the concept of an excessive society where the exact opposite is going on.