Mark of Detection Half-Elf Artificer.
I'll start off by saying that your general character concept would not be welcome at any table I have ever played at, the same as any other character concept that seeks to actively sabotage the party's success.
That said, if you wanted to play an actually competent vampire hunter, I'd say that the Mark of Detection Half-Elf Artificer would fit the bill of a character with divination spells who doesn't rely ofon magic to fight. The Artificer doesn't have much in the way of divination spells, but it's still a half-caster that can focus pretty heavily on armed combat rather than magical combat (especially with subclasses like the Armorer or War Smith); the Mark of Detection Half-Elf adds a bunch of divination spells onto their spell-list.
You'd probably be looking at a statline like Str 10 Dex 14 Con 14 Int 16 Wis 12 Cha 8, using the standard point-buy for 5e, and you'd be able to fluff all their infusions and spells as vampire-hunting gear they've built.