D&D 5E How to role play warlock

[grimslade]

My hexblade will have an unconventional pact. His patron is a sword, in the spirit of Black Razor or Stormbringer, that was wielded against his mother, a great champion of the realm. His mother was pierced by the blade at the same time her spell destroyed the blade. This left a very small fragment of the blade deep within her. She defeated the BBEG who owned the blade and settled down to raise a family. While carrying my character, the fragment traveled through his mother's body to the infant warlock. So my warlock is born with a fragment of a terrible artifact within him. The blade that wants to be reforged. The Blade pact ability to summon my pact weapon is skinned as the blade forming from my flesh, blood, and bone. Eldritch blasts are shards of soul-stuff trapped in the fragment violently expelled. The Blade wants the warlock to grow stronger, with every new ability it comes closer to consuming its host and being renewed using the warlock's own body as the fuel for its rebirth. I imagine it will whisper to the warlock like the symbiote to Spiderman or Venom. Like any intelligent weapon, it will attempt a battle of wills to control the warlock. So not a traditional patron.

 

[Al2O3]

It sounds to me that you want help with "how to play a less-than-devoted servant of the Raven Queen" rather than anything connected to the specific class. The story you have given could work just as well with a cleric or paladin as the class.

The two central questions I think you and your DM need to figure out are: what are your character's goals, and what are the Raven Queen's goals?

Another way to think of it is in terms of actors and conflicts. From what you wrote here I see four main actors to consider:
-Your PC
-the party
-the Zhentharim
-the Raven Queen

If your character could change something about their life, what would it be? Something like that could give you a goal for your character that you can work towards regardless of the other actors and their goals. Maybe there might even be times where you have to choose between working towards your own goals and those of some other actor. That is where conflict comes in, which is part of what makes story and gives your character a personality.

The party probably has a common goal of some kind (the plot), and the other members might also have goals that could contribute to conflict.

You mentioned that the Zhents saved your character. Were you ever a full member? Are you still? What do they want you to do, and are their goals compatible with those of other actors? Having your character trying to balance between loyalty to the organisation and loyalty to the Raven Queen would probably help with involving both of those into the story.

And the Raven Queen herself. You know some of her goals. But why do you work to help her? You could be truly loyal, despite the forced start. Or maybe you would prefer to fail and sabotage from time to time, maybe as protest against being pressed into her service under threat of death.

I'm terms of how I've seen others handle class connections to the Raven Queen:
We have a shadar-kai Shadow sorcerer in my party in ToA. He is being role-played as very loyal to his queen and having met her. The way it comes up in play is taking trinkets she would like when we loot, refusing temptations from other gods, invoking her teachings or power in conversion and making sure to perform rituals and prayers at every long rest.