Black Blood Brothers
I think growing up I was obsessed with demons and vampires. After all... they are OP by nature. Demons and vampires crush humans in fights, outlive humans by longevity. I digress though.
Black Blood Brothers is a short 12 episode anime about vampires set in Hong Kong. I really liked it because vampires are amazingly interesting. And so are brothers. I've always wanted a brother... either younger or older. I got a younger brother but then... he's too weak and no fun to be around.
This series has a korean ending song. Which is really beautiful. I think my favorite type of music is still ballad.. and this anime it. The action in this series is good... although it's mostly one sided. You basically have the god tier characters and then the fodder characters. Which is exactly my type of anime.
You see the two brothers traveling together and meeting people. And then through flashbacks you understand how the characters all relate to each other. I guess the story is kinda your typical fallen hero story. Since Jiro (the elder brother) was the heroic vampire who slew the one master vampire back in the day. But now he's weak from lack of combat. And then throughout the series he just refinds his determination and redeems himself as the rightful badass.
I think the shows main selling points are the ending song (serious), the vampire powers and characters. I really liked it back in the day and I think I'd rewatch it even now. Series like this show I would say are Chrno Crusade, and Trinity Blood?
tl;dr - watch this anime for the vampire powers and fights, the interesting characters and the amazing korean ending song