So I just got my first level up after joining late in a campaign (I started at lv 5) And decided I wanted to multiclass into a hexblade warlock. My main class is a homebrew samurai class and my character is trying to recover his honor after fleeing from a battle to protect his hometown. In my backstory, I said I fought in many duels to the death trying to recover my honor but the only thing I've done in the campaign so far is killing a bunch of racist dwarves. I'm trying to find some way to fluff this multiclass but cant figure out how, can someone help? some ideas i were thinking were like someone possesses my blade like one of the people i killed dueling or somthing.

You've won many duels and sometimes, depending on the level of difficulty during, you kept something from your defeated opponent as a trophy. Perhaps one of the more recent duels was a particularly difficult bout in which you barely came out on top. You noticed throughout that, the source of your opponent's power seemed to be coming from their blade, which somehow was conjured from thin air at some point (as far as you could tell). So this sword became the trophy that you acquired from that particular duel.

Upon defeating another duelist sometime after (with this new sword, the magical properties of which you have yet to reveal) some otherworldly being makes itself known to you, whoever your patron happens to be. They reveal to you that you currently wield the sword of one with whom they made a deal. This deal is offered to you in continuation. Your patron shall grant you the power to conquer your foes and regain your honor on this one condition; that each victory you have must be spoken in the honor of your Patron and the souls of the fallen presented to them in servitude through a small ritual.

You will eventually learn how to summon the blade from thin air (pact of the blade) and even change the form of it to suit your needs. Over time you will learn some the tricks of that opponent who - in their demise - gifted you this patron, this new power, this new life, and ultimately your Honor.

Quote from McSimoIII >>

So I just got my first level up after joining late in a campaign (I started at lv 5) And decided I wanted to multiclass into a hexblade warlock. My main class is a homebrew samurai class and my character is trying to recover his honor after fleeing from a battle to protect his hometown. In my backstory, I said I fought in many duels to the death trying to recover my honor but the only thing I've done in the campaign so far is killing a bunch of racist dwarves. I'm trying to find some way to fluff this multiclass but cant figure out how, can someone help? some ideas i were thinking were like someone possesses my blade like one of the people i killed dueling or somthing.

 The Raven Queen appears to you in a nightmare about your mother and reveals she likes it when you murder dwarves and wants to reward you for it.  You awake, your heart thumping wildly, to discover you have strange new powers.  Perhaps it wasn't all just a dream...

Don't have something possess your blade.  It's a bizarre internet meme that Hexblades carry their patrons in sword form.  Literally zero Warlock subclasses have the Warlock carry their patron around like some sort of trinket.

Just an RP question but you are trying to regain your honor from fleeing a battle. Would making a deal with a patron to give you more power help you regain your honor? Or would it hinder regaining it because of the patrons assistance. Kind of like you are running a marathon, you can’t complete the last mile, but someone picks you up and carries you over the finish line. Did you really complete the marathon?

I’m not saying you shouldn’t multiclass, but are you going for regaining honor at all costs? Or plan on playing off no matter how you try you cannot regain it unless you do it yourself (kind of a love-hate relationship to the patron)