The ideal candidate for a soul-graft depends on arcane magical properties, but that is no reason not to also expect some more... mundane similarities.
There's a pop of air behind his back. "Why is this taking you so long", an inhuman voice complains.
Gord turns around already knowing what he's about to see, even as Lann and Seelah shout at him from opposite directions.
This is it, then.
A feeling of resignation washes over him. He takes a step back and it's so slow, crawling like molasses through the air as Lann fires another pointless arrow and Seelah charges in to die by his side and the monster watches the ridiculously futile resistance with idle curiosity, like ants it can't begin to understand but will step on all the same.
And beneath the resignation, slowly building rage. I am not done yet! How dare you make me give up! I refuse to die! How dare you call yourself Gord and resign yourself to death! Get out my head, IMPOSTER! I will KILL this wretched monster that DARES make me despair!
The wound on his chest reopens and weeps blood, and he watches it as the moment stretches to taffy. Is he even in control of his body anymore? What's happening to him?
Fight the rage, whispers another voice. You don't need it to win. Take the Light of Heaven into your soul. Smite the demon with holy power. Join us in the fight against Evil.
And that one, somehow, snaps him out of it.
How dare any of these voices get into his head and tell him what to do.
How dare Heaven bid him sell his soul for power, on this day and after his entire life. He'll die first.
But he'll die as he lived: on his feet, and fighting.
Shut up. Both of you.
I am Gord. And I will DIE FREE.
Gord's and Seelah's swords (and Anevia's arrow) hit Savamelekh at the same time, with about the effect you would predict.
Also, a giant bolt of holy energy smites him literally to the ground.
...he gets back up again.
What the abyss? That one stung! It wasn't anywhere close to lethal, but demons don't get to be a hundred years old by sticking around to find out if they can take a paladin whose weird smite can literally knock you off your feet.
"Hosilla! Destroy this vermin!" And he's gone in a pop of air.
She's still stuck behind this blasted spiritual ally (luckily Gord's been too distracted to make it move to chase her) and, also, that paladin just knocked Savamelekh off his feet!
She'll make a quiet tactical withdrawal, how about that, and totally carry out her orders later.
"Praise the Inheritor!" Seelah says fervently, and then "praise be to the Light of Heaven!"
Light? You did that, didn't you?
"Is the demon going to come back, or can we chase down that cultist and help Wenduag and the younglings?"
"I don't think I did it in the first place! I heard it sort of speak in my head but it didn't exactly ask me for permission! I've said I'm only carrying this holy sword until I find it a deserving wielder!"
"It offered me power for mine," Gord says darkly, but he can't really muster up the necessary emotion because he's still feeling weak in the knees from sheer relief. "We will give you the power to smite demons if you make us a part of your very soul and agree to smite all of Evil with us, all that crap."
Did the demon try to dominate Gord or something? She flickers detect evil at him just to be sure.
Oh no -
If he's dominated they probably can't take him in a straight fight (and she doesn't want to ask the Light to smite him), so she'll try not to let him immediately realise she noticed.
She'll... nonchalantly walk past him and down the hall a bit to check up on Anevia, how about that.
As the only person in the party besides Gord who is sane appreciates the threat level of a vrolikai, Anevia is also feeling a bit weak in the knees, although she's very practiced at not letting it show.
She's also enormously curious about what just happened, but since Seelah just said she doesn't know for sure Anevia won't pry, in case Seelah has a good reason not to say anything more; she doesn't want to force an inexperienced paladin to dance around the truth.
"Are you feeling well?"
"I - yeah. I wasn't hurt, just - very surprised I guess, and not sure what happened?" And clearly distracted by something.
Now, how to actually do this... She does have some practice passing secret messages, but she doubts Anevia knows Kushite thieves' cant and anyway she's rusty, so.
Seelah takes out a piece of paper and a bit of charcoal (meant for leaving messages in emergency if they ever got separated), glances back to make sure Gord is still in the other room, and writes: GRD DETEC EVL.
"Did anything like that ever happen to you before?", Anevia asks in a completely unremarkable tone.
"No! I mean - I never tried before, because I... didn't have a reason to think... it would work?" Seelah offers. Damn it, the cover conversation is mixing up with her secret messaging. She's a paladin, not a wizard!
"So... maybe you could always do that, or at least since you found the angel's sword, but you only noticed when you were desperate enough to actually try?"