In the movie version of Escaflowne, A Girl in Gaea, the relationship between Van and Folken is quite different. Defined by a different past, the brothers are filled with sorrow and a deeper hatred of each other.
In their country, an oracle decides who will become the king, rather than birth rite. When the time of choosing came, the sign was on the side of Van instead of his older brother Dune. In retaliation, Dune (who changes his name to Folken) creates his own army which he calls the Black Dragon Clan, and lays waste to his homeland. He personally murders his father, telling him that he will kill Van with his own hands. Van, who is still a rather young boy, is a king without a country and a man with only one purpose left-killing his brother.
To Dune, their relationship was defined by Van taking what should have belonged to him. Instead of seeing him as a brother, he could only see an usurper-a person in the way of allowing him to take power. He became sullen and dark, bent, not on ruling but on destroying. Although he does much to accumulate power, as Sora comments, it doesn't appear to be the end to his efforts, but rather the means. He plainly states that what he wants is the end to suffering, namely his own.
Can anyone really forgive a brother who kills his parents and swears to kill him as well? Van had to suffer the loss of his entire family, as well as the loss of his kingdom and people, and all of this at a young age. Van claims that his only remaining purpose is killing his murdering brother. Does he hate his brother? Certainly to some degree he must, but as a child he adored his big brother, and something like that never really goes away. Because of his brother, his life has been reduced to fighting and killing his enemies. Only Hitomi's influence allows him to believe that there might be a life for him after the end of the war.
Van joins those who share his same goal, ending the oppression and destruction of the Black Dragon Clan, but he does not fight with them. He considers himself "always alone." Folken is in pain, Folken suffers, and Folken plots to destroy the world. Both men suffer alone, with death as their only comfort. Folken is specifically avoiding the future, and Van doesn't seem to believe that one is possible. This is the point at which Hitomi enters the picture.
She too is in pain, feels cut off from everyone, and only sees people hurting each other. Her wounded and lost spirit resonates with Folken, who summons her to his world, but it is Van whom she first meets. She sees herself in him, in his loneliness, and decides to stay by him no matter what. Her loyalty and desire to show him that he is not alone allows Van to prevent Escaflowne from destroying Gaea. Folken had believed that even if Van did gain control of Escaflowne, his pain would cause him to unleash the mecha's power and destroy Gaea anyway. When he was able to stop Escaflowne, all that was left was for Van to face his older brother.
Folken still believes that Escaflowne wants him, and that it shares his desire to destroy Gaea and he will kill Van to gain its power. Van, however, has come to believe that is future doesn't have to end with the war, and he no longer wants to fight, specifically with his brother. He refuses to fight and only uses his power to defend himself from his brother's attacks. When Folken meets his fate, Van cries out, and the man once known as Dune recalls happier days. A young Van would run to him, calling "brother" and he wasn't alone. Before he dies he says, "A sound I had long forgotten."
In the end, both brothers got what they wanted. Van once again had a home, a future without fighting, and someone who would always be with him, even if they parted. Folken got his analation, but not before learning that he was not alone. Whatever suffering they may have caused each other (intentional or other wise), the two were finally at peace with each other.
The main difference in their relationship between the anime and the movie is that Folken actually wants to kill his brother. In the anime, he asks him to join his side and tries to have him captured instead of killed. Folken gets angry that his brother disrupts his plans (which he believes to be noble) but he never really hates his brother. Van, on the other hand, does hate his brother for his betrayal, but he still loves him on some level, even if he doesn't like to admit it.
In the anime, it is Folken who returns to his brother and it is only when he dies that Van realizes that he still loved him. The movie, however, has Van return to his brother (though it is not to join him in his battle) and Folken who remembers the love he felt as he dies. Although the animosity is much stronger in the movie, the bond of brotherhood is strong enough to survive even the worst of betrayals and neither man is destined to loneliness.