Castlevania: Curse of Darkness
In the three years following Dracula's defeat at the hands of Trevor Belmont, the lands under the Demon Vampire's control still haven't recovered. Demons, devils, and nasties still roam the lands, and the Curse of Dracula's Darkness (name drop) still hangs heavy over the territory.
It's within this time that one of Dracula's followers, a devil forgemaster (guy that makes and trains demons for Dracula's castle) named Hector, has left the domains for greener pastures. Hector apparently decided that the whole "being evil" schtick wasn't all it was cracked up to be, so he left to make a new, less-evil life for himself. He went out, got married, and started up the good life (probably forging non-evil demons for domestic use).
But this is a Castlevania game (and, as we at the Inverted Dungeon have noticed, women get the short end of the stick in this series), Hector's wife is soon killed by another forgemaster (and fellow co-worker of Hector's), Issac. Issac felt that Hector never should have left the fold, and his big plan was to kill Hector's wife to lure Hector back to the Demon Castle.
And sure, it worked... if only so that Hector could wage unholy vengeance on Issac. And he did.
Unfortunately, as it turned out, killing Issac was all a plan by Death (Castlevania does like its twists). The vengeance Hector desired was a product of Dracula's curse. Had Hector not thrown off the curse himself, he would have been the perfect vessel for Dracula's resurrection. Instead, a less perfect ceremony was performed using Issac's body.
Hector plugged onwards to the Dark Lord himself, and there the two fought. Dracula was defeated, and Hector used his power to clear the land of the curse... for a time.
This is the only game to state that Dracula's powers lay over the land even when the Dark Lord isn't around. It's a fair assumption, and does tie in nicely to Simon's Quest where Dracula's minions are still around even though the Dark Lord is dead.
As mentioned, Dracula needed a host for his energy, for his soul to possess. This isn't always the case, but often a host is needed when Dracula is dead and isn't expected to rise again for a while (see also Castlevania for the Nintendo 64).
During the course of the game, Hector encounters Trevor Belmont. Trevor is adventuring around the countryside, working to rid the land of Dracula's evil. After playing through the game as Hector, Trevor is unlocked for the standard second-quest style playthrough.
Oddly, the whole "Demon Forgemaster" angle was never mentioned before this game, nor have the characters or the class shown up again. It's one of those weird maguffins that's mentioned and then ignored... like the Crimson Stone in Lament of Innocence.