If you could rework DRK and base it off of one DRK themed anime/video game character

[Shurrikhan]

Bloodspiller is literally lifted from the panel of Guts' fight with Grunbled. It's the strike that sundered his warhammer and went into his shoulder.

In the only version that'd, by necessity, give enough panels to tell what the hell the sword is doing to that extent, the fight is literally Plunge, DRK Skull Splitter, DRK Skull Splitter, and then Plunge with a horizontal twist instead of a front-flip. At no point does he just spin his sword once at let gravity, alone, take it, as per Bloodspiller. He adds his own weight behind and muscle to each strike.

Furthermore Living Dead is basically lorewise the same as the Berserker armor in that it just kind of holds you together so you can keep swinging for a bit longer.

That's literally the same as Holmgang. And given how little on-demand healing is available to Guts, and how long he's typically wounded after using the Berserker armor, he sure as hell isn't being quickly healed to full to avoid a Doom state.

Again, love the character, but gap-closer aside, his powers and source of powers (his kit and lore) are almost pure Warrior (the Berserker), not Dark Knight.