Balgus was a loyal subject of Fanelia and a father figure for Van at the same time. Fighting against a Zaibach Alseides armed only with an enormous sword (as he did in episode 2) is beyond the ability of a normal swordsman; in fact, such feats are only possible by one whose abilities surpass those of a human being. However, there are not many such consummate sowordsmen in all of Gaea. It is said that in the last several decades, only three such men existed: Adama Ish the Lion Man, Lig vieta the Doppleganger, and Balgus.
Even these Three Swordsmen of Gaea - which they are called with are and respect - did not reach this level on their own. In addition to their natural talent, it was essential for them to possess unimaginable dedication in order to become such master swordsmen. But even so, attaining supernatural skill levels could have been possible only with guidance by the Altanteans. So why did the Alanteans give such guidance only to these particular individuals? The truth will never be known for certain, but it seems that the Alanteans - then already a spiritual existence embodied in the world of Gaea itself - intended them to protect Gaea. In other words, they were destined to be heroes.
However, such Atlantean intervention seems to have been commonplace when it comes to protecting critical stages of Gaea's history. (The appearance of Van's mother, Varie, is one such example.) It is uncertain what exact roles these three swordsmen played in the past. Nonetheless, by showing that the power of the mind surpasses physical strength, they served their purpose...at least as far as Van is concerned.