My suggestion...

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Since Person A is some kind of hunter, he finds person B earlier than others and proposes him a deal. He will help B get out of country safely if B helps him enter those iron doors first. (here he may even consider that once B opens the door, he will give B to the hunters but that depends on his moral compass). B agrees since this is a way for him out of both Mages and hunters.

However the voyage together proves to be harder than they thought. Many times they have to fight side by side with mages and hunters who hunt them down. This builds a bond between them despite their dislike of eachother. (And trust me it does. As an ex soldier i can personally say that fighting together increase bonds no matter how much you hate eachother).
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I hope I understood your story and question. Goodluck and keep on writing ;)

Hmm, interesting. Thank you!
Thank you as well! I have no personal experience with fights or anything, but I do imagine it strengthening the bond.

I see no reason not to, once they trust each other. That would likely be the main obstacle to friendship. Beyond that it's whether their characters are compatible. If they share something in terms of world view and ideology, that could make for a strong bond.

Any stressful situation in which they need to rely on each other is likely to create a bond (and build trust).

Even when they come from completely different sides?

My advice: Don't think, just write! It's easier than You think. ;)

The stuff I write is mostly reviews but I'm trying to develop my own style.

or what if the hunter and the hunted are the same person only the hunter is the earlier or younger self of the hunted and
the hunted is the older and wiser self of the hunter who in turn has to warn or advise the hunter

Uh oh, I smell time travel. :)

uh uh i smell the doctor

Sides mainly mean mistrust. It can be more than this if there has been propaganda built to demonise each other, but I didn't get the feeling that was the case here. Even then, there's no reason all people will fall for this, and in this particular case you've made it clear that person A has moral problems with what he's doing. So my feeling is that different sides in this case just manifest as an issue of trust, possibly even one that can be easily resolved.

Do you mean Rex Harrison with the PushmePullYou?

If commercialism has anything to do with it, probably sharing a Klondike Bar.

I think it depends a lot on Williams, but I'll come to it a bit later.

Being on opposite sides isn't by itself a huge barrier. It's still a matter of trust. People are taught that their enemies are out to get them, but anyone who isn't a fanatic will likely be willing to accept a person of the other side as a person once it's clear that the "enemy" doesn't wish him or her harm.

In this case both are already outcasts from their own groups of their own will, and don't believe that things are black and white. Both have reasons to stick together, Williams for finding what happened to her family, the mage for protection from his or her own group. So this partly falls back to the question of whether they could have been friends had they been in the same group.

I assume that you want them to be friends, and I think, given the above, that it's entirely plausible (if we assume that only the circumstances are keeping them from being friends). Still, a lot of it falls to how Williams will behave. Williams has already saved the mage, so the mage would think of her favourably. On the other hand, Williams only wants to use the mage, and if she reveals that tactlessly, the mage is likely to feel she's no different than the illegal mages.

Here it's up to you to determine how their behaviour will help or hinder the friendship. Williams will likely need to be convinced that the mage is more than just a tool. This could come from finding something they share (like loss of their families) or from the mage doing something "beyond the call of duty", such as saving her life back in the extreme case, or just showing gratitude in nice ways. The mage may be a little paranoid at this point, but if Williams treats him or her right that might alleviate the fears.


tl;dr: These are two people who have good reasons to work together; they aren't at cross purposes. The obstacle to their friendship is realising that.