It's sorta hard to convert the vibes of Bloodborne to D&D, because FromSoft games are big on skill and timing and reflexes, and D&D is just luck of the dice with a small bit of tactics.
So I'd try to lean into the tactics side of things, and make a character with a variety of reactions, and maybe some buffs you can apply that require concentration so you need to gauge when they're safe to use. A Battlemaster fighter multiclassed with Great Old One warlock gives you some pretty interesting tools, even if they're not especially synergistic.