By the year 1476, it was clear to the people of Transylvania that evil had not been knocked off its course. Indeed, it was proving difficult to contain a Dark Lord whose thirst for revenge was much greater than his thirst for human blood. Not yet apparent to Belmont heroes was Dracula's propensity to feign defeat and lay low for many years as his power regenerate, they were just as much shocked when the Count took the name Vlad Tepes and used such a declaration as the platform for his campaign's most vicious assaults, which would finally alert the entire world to his presence. The first challenger would no doubt be Trevor Belmont. The timing of the game (Dracula's Curse), twenty-six years after the adventures of Sonia, strengthens the theory that he's indeed the son of she and Alucard, as hinted upon in Legends' ending sequence. If Trevor was instead meant to be her brother, it would put him somewhere around the age of forty-two at the time of his adventure, which doesn't seem likely. If true, it's an important event in the family's evolution, because a relationship forged between two such beings would do nothing but expand the scope of the bloodline's magical and superhuman propensity (without infecting or diluting the chromosomes even in light of Alucard's vampire blood). In an eerie twist, this would make Dracula the grandfather of Trevor, creating a sort-of translucent bond between the Yin and the Yang.
While the family would much later go down in Romanian legend, the current scene wasn't rosy: The family was within Warakiyan communities heavily mistrusted by a people who were highly suspicious of their power. Sometime after Sonia's exploits, this prevailing sentiment boiled over and the family was exiled from Warakiya, asked to leave or else. It wasn't so much fear (as it says in the Dracula's Curse's intro) but that the people felt the family's superhuman power made all of Warakiya a target; furthermore, there was a prevailing notion that the Belmonts could go awry and use their power for wrongful means. A Belmont warrior had once renounced his association with the Church, when Leon had no other choice, so what was stopping them, panicked citizens thought, from again breaking a trust? Fortunately for them, Trevor had no plans of straying from the path of righteousness. Dracula's forces would begin terrorizing the countryside and sending the clear message that it was their time. When the embattled Church, its knights overwhelmed, was faced with no other options, it turned to its allies in the Belmont clan, who upon its request would pursue and defeat Dracula, the cause of the chaos. Trevor took command of the Vampire Killer and the five sub-weapons and set course for Dracula's castle.
The most notable event in Trevor's adventure was his eventual meeting with Alucard, who had decided to stick around for a while just in case. In time, he came to sense that this decision was wise, for his father had not been truly defeated and the war had only begun. It seemed that despite his best efforts, a confrontation with his father could not be avoided. Thus, he waited and made a calculated appearance to ensure that his unknowing son, a much-desired ally in the war, was taking the proper measures to counter a threat as great as Dracula; he'd do so via another of his now-famed test battles, no less. He to Trevor made no acknowledgment of his recent past, nor did he hint that he was the former lover of a one "Sonia Belmont." Even in Symphony of the Night, when approached by Maria, did Alucard only faintly remember Trevor. Was Alucard's memory hazy from too many years of isolation--sort of Alzheimer's disease for vampires? Well, of course not. Logically, he couldn't have known about Trevor in storyline because Legends was created in 1998, eight years after Dracula's Curse and one year after Symphony. This is an unfortunate element of prequels. To make sense out of it, because we can't ignore it, we can only say that Alucard was a master of playing stupid, if not of manipulation, in this case not to further complicate things with issues of "who's whose father?" and such when Trevor already had enough on his plate. (This is not far from the beaten path, since "deceit and feigning ignorance" [or "Obi-Wan Disorder"] is basically his modus operandi in Aria of Sorrow.)
According to the in-action storyline of Dracula's Curse, Trevor only met with two of the trio of helpers--a group that consisted of Alucard, Grant Danasty and Sypha Belnades--which works to eliminate at least one of them in the grand scheme even though the future of the story depends on Trevor meeting both Alucard and Sypha, who are placed in opposing paths. It could be argued that he met all three allies, who they teamed up to defeat Dracula, but this counters game sequences where the acceptance of one leads to the loss of another, with, say, Grant Danasty leaving Trevor behind when he elects to receive Sypha or Alucard's assistance. What does Koji Igarashi, whose favorite series title is the very same Dracula's Curse, think of this? "Screw it," he says for another set of seemingly canon events. No such parting of ways ever precipitated, and the trio did indeed team up to destroy the Dark Lord. In addition to the official timeline, which confirms this, Igarashi hammers it home in the future Symphony of the Night, where Alucard fights against the enemies Fake Grant, Fake Trevor and Fake Sypha, one of which he would never know if Dracula's Curse in-action storyline weren't only for the sake of in-game exposition.
As the endings tell us: Sypha ends up staying with Trevor and taking his hand in marriage (as the manual of Harmony of Dissonance confirms). Grant, who forges with Trevor a great friendship, sticks around and helps in the rebuilding of Warakiya after its destruction at the hands of Dracula's dark forces. And Alucard, who as he expected found tremendous pain in confronting his father, finds it best to soothe his inner wounds by finally submerging his power and, as fate would have it, staying out of the equation for at least three hundred years. The most important relationship here, then, is that between Trevor and Sypha, who would give birth to the children who would be next in line to counter evil. Since Dracula was only growing more powerful over the centuries, the Belmont chromosomes were ever-expanding in power, too, what with Alucard and Sypha's powerful genes now mixed into the bloodline. So it was at the hands of Trevor and friends that Vlad Tepes Dracula saw painful defeat that resulted in his spirit's banishment to a netherworld. (And while Castlevania: Curse of Darkness tells the tale of a close-proximity resurrection, thwarted by the turncoat Forgemaster Hector and the actions of the vigilant Trevor, it's a chapter of the story that is irrelevant to the overall cycle of events that sees Dracula's revival approximately once every hundred years.)
Things continued on like this over the coming centuries, with a standard series of events: (1) Dracula rises. (2) Belmont warrior steps up to the plate and slays him. And (3) Dracula is forced back into an unholy resting place (the Chaotic Zone or perhaps Hell) until the world's evil again grows strong. The Belmont clan persisted in its evolution, too, as the Belmonts would continue to engage with powerful beings such as Sypha. The family would over time branch out to multiple territories, with Trevor having multiple children, with those children growing to have multiple offspring, and son on. This would lead to a problem: If there were now many suitors worthy, which Belmont warrior would be selected to receive the title of Vampire Killer and face the task of slaying the Count (or battling evil in general in the years between his frequent resurrections)? In order to keep in peak condition the line of warriors, it would have to be a heavily contested honor, judged ultimately through painstaking trial. Christopher Belmont (perhaps the grandson of Trevor) was one of the last to receive the honor through commonsense lineage. And over a hundred years later, the same was said of Simon Belmont. True, both were forced to fight Dracula twice, but in retrospect, those battles can be considered "one" since it may be wrong to assume that a singular Belmont confrontation with Dracula should a single fate-necessitated battle make.
The tides of change started to take hold around the time of Juste Belmont (who is rumored to be the great-grandson of Simon). As the ritual came to exist, the Vampire Killer and mystic weapons would be left to the possession of a clan member deemed to be most worthy through his actions--this under the ordinance of the elders. As discussed, this was often an easy choice left to common sense--for Sonia, Christopher, Soleiyu, Trevor, Simon, etc.--as only one worthy warrior existed. But as the chromosomes evolved, the family continued to grow and expand into other provinces, which in turn led to offspring whose last names were not "Belmont." Who would be chosen to be the successor? The first known contest was between Juste Belmont and Maxim Kischine, who trained together and in practice competed to earn the title of "Vampire Killer." Up until now, the "curse" of having to hunt Dracula was seen more as a burden, but as the Belmont warriors, under any name, grew more powerful, they became more confident and impetuous, and some almost wanted the honor that came along with slaying one such as Count Dracula. So, as mentioned, it often became a competition between family members, be they friends or rivals. Some, as you'll find, learned to coexist by teaming up or through unselfishness, whereby a comparably powerful yet humble subject would realize that the other was the better bet to combat the most ultimate of evil.
Richter Belmont (perhaps the great-grandson of Soleiyu Belmont) was in the class of those who would not have to "earn" it, and true to the history of no competition, it emoted itself upon him as a sense of burden. In his case, the only competition, Maria Renard, was out of the picture due to her abduction at the hands of Dracula's dark forces, so it was up to Richter to save Maria rather than compete with her for the title of "Vampire Killer." In the true-to-canon Dracula X: Rondo of Blood, Maria becomes a fighting ally, an alternate hero, after her rescue, but this is seen (especially in its interpretation of the "Final Stage" battle in Symphony of the Night) as only a "helping" role. No--this was Richter's battle, and Maria knew it.
As was the case with both Simon and Christopher, Richter appeared in two series titles, the second of which saw him relegated to the role of hero coaxed to the side of evil by a spell placed on him by the dark priest Shaft during their previous encounter. The result of his absence brought about an interesting event: The spirits protecting Alucard's sleep sensed a hero-less emergency scenario, and the powerful forces (perhaps alerted to these happenings by the Poltergeist King, divine protector of the lineage) again called upon the proverbial pinch hitter to deal with the new threat. After rising from his slumber, Alucard headed toward the freshly risen Castlevania. And when he met a man claiming to be "the ruler of this castle," Alucard detected a familiar aura. In this particular case, his ability to aesthetically sense Richter's bloodline may have been more indicative of his very close bond with the family than of his vampire instincts; in effect, it was traces of his own half-breed blood that he was detecting.
Had Alucard not been beckoned from his resting place, the lineage might have been dead right there. Otherwise, had Alucard destroyed the possessed Richter, neither he nor Maria would have ever been the wiser to Shaft's game. Would such an occurrence even be possible? Not according to the Yin Yang order that exists to haunt those such as Dracula: Since the "greater good" had been removed, Alucard would not fail--he would do his job in taking its place until the rightful order was repaired. And not even those who wish to confuse the forces of nature, like Shaft, can stop the cycle and its eventuality.