but clearly, or for long;
I think a word got eaten there? Unless my knowledge of English is failing me.
It follows then that if the presence is away from us, and necromantic in nature, maybe try to command it while we're all inside of Eko's ward (or a new one if it's too far away). The ward's shielding effect might be enough to disrupt or remove whatever outside influence is keeping us from taking control of the construct.
That's a good idea for a future experiment, but there are a few problems. If you remember, minor wards against necromancy work by altering and blocking necromantic senses. So unless those sensors are used to receive orders/magic (unlikely) it will not work. You'd need something like a major ward or better yet a sanctuary. And just to be on the safe side, ensure that such a ward will only disrupt spells going in or out of the area and not spells in the area itself, because if they disrupt the magic of the creature, we risk loosing it (and Omo's soul if we haven't gotten it fixed by then).
Ask Eko if he knows anything about contests of will between casters.
Yeeeah that might be useful. Something like "There's something more here, not sure what."
If we go with that suggestion, maybe tell him that we feel another presence. Like this thing is fighting our influence more than it should be able to and that this has to be coming from somewhere else. That we momentarily felt another presence or some of its feelings. Descriptive but keeping the details of what we were trying to do vague.
Eko has that trait Clarity that lets him resist things better. Maybe he could help us achieve a lesser form of that? Or some other kind of meditation that could aid us in mental combat?
I think the necromancer sealed himself inside the golem - or maybe just his soul - and has been stealing souls either to prepare to revive him or to sustain him. A personal theory of mine is that he's trying to do the former, but doing so is actually impossible - he's just really desperate and maybe a bit insane.
That is very clearly not the case. It was stated that the opposing influence came from somewhere outside the golem. So it couldn't have been inside it. And we know that the one who is the assumed creator of the golem (Balkoth, unless I'm misremembering the name) died at the end of the Golgothan war somewhere very far away from this forest (Golgothan Swamps, the temple of Death if I remember correctly). Even if the golem was created by someone else, like one of Balkoth's necromancer lackeys and he/she had put her soul or even part of it in it, we would had been able to see it. Souls are incredibly complex, while the necromantic energy of the construct was very simple. Nym said it looked nothing like Omo's or Eko's soul.
That doesn't mean that there aren't souls involved though. Maybe Balkoth used the soul of one of his followers to create a semi-immortal golem administrator. A guy that has been imprisoned in some sort of construct and forced to follow certain orders and make the golems act a certain way. Or some variation of that. Maybe he's tasked with gathering souls. Has some sort of soul vault. Or soul fridge, if he's using them to sustain himself.
People expressed surprise that zombies were active so long after Balkoth died. Maybe spells (the continued existence and operation of magical energy of all faiths) need the wizard to be alive to continue functioning? Maybe that's what the administrator does, makes sure the constructs remain functional and continue following their orders by attaching their magic to him?
Or maybe it's related to the unexplained bypass of Eko's wards. We know that zombies somehow bypassed the wards. We know that zombies can bypass minor wards with command undead. And we know that whoever is controlling this thing is much more powerful and has much greater range than we do. Maybe the administrator influenced those zombies once they entered his range and made them bypass the wards? Or maybe Curo has found out about the golem and is using it for his own nefarious goals? Maybe he has obtained an artifact that can increase his range tremendously?
Although the administrator might not be fully human or fully sentient. Or maybe he can't control the golem fully. After all, if he could, he might have done something different with the golem. Maybe he's only part of someone's soul. Or maybe his dark feelings blind him.
It is possible that it is Omo's soul that was repelling our influence,
Possible, but not very likely. The feelings did not feel like Omo's, for one. And he'd have no reason to resist us, unless he is doing it unintentionally.
I suggest that we imitate the construct and create our own rope of necromatic energy to try to grab the ball of vitality we believe to be Omo's soul and return it to his head.
Not really necessary to make a rope. The soul is already inside a necromantic "bottle" of sorts. All we have to do is carefully move that bottle of necromantic energy.
That's going to be my long term suggestion. Just do the soul transfer now, then use our rope to tie the creature here for us to experiment on later while Eko takes care of Omo back in the camp and maybe makes a sanctuary or major Ward to make the experiment area safe and stop necromantic spells from entering it.