I think at this point, it is clear that the system of picking the next Paladin is rigged, but I want to know if you still think it’s possible for Rin to become the Paladin at one point?
In terms of skill, all five meisters are necessary (the Tamer one always confused me, because it’s a rare talent to have), and I assume a lot of dedication, training, and intelligence. I don’t like the anime-filler ending, but I do see Yukio as a better candidate (though not at the age of 16 and with better mental health).
Additionally, I think Rin could be picked for his sheer strength and firepower for the position of Paladin, which I think is a similar situation for Angel (they both seem to be lacking in the intelligence department, with Angel having Lighting do the thinking for him).
Shiro Fujimoto is a canon Paladin with the widest range of skills practically shown in the series. Certainly the only one so far who has favored a gun over a sword, and has actually used both at once when fighting a newborn Rin.
The system isn't rigged so much as entirely secretive. We don't even know how it happens to know if they're rigging a vote or if it's just which of the three Grigori + the Honorary Knight (Mephisto's position) can hoist their candidate to the position first.
The Paladin before Shirou was a man named Abel, and he called Mephisto 'father' as he was consumed by Satanic flames in the Blue Night, so it seems fair to say that being a clone/descendent of the Grigori + Honorary Knight gets you in the front running of being a Paladin, seeing as we have Abel=Son of Mephisto, Shirou=clone of Azazel, Angel = clone of Lucifer.
Which also is an entirely reasonable thing to require as it seems that the more demon blood you have, the easier time you have advancing in the ranks.
Quick side note on the tamer thing, and on all the meisters. All meisters have multiple subclasses. Tamers are just exorcists who work with/use demons in their exorcism work. They're not necessarily all summoning them. For instance, there's a subclass specifically for tamers who specialize in the demon farm work and in cross breeding. Personally, I'd love to get more details on that. Just like the doctor meister isn't necessarily about medicine, it can also be using poisons to your advantage. I imagine that the long list of Paladins has had a wide variety of which versions of the meisters they're bringing to the front.
I think that lineage and skill level aside, the real key to who is becoming Paladin depends on something else. There's not much to back this up other than the way we know Shirou was trapped, and how tied to Mephisto Abel seemed to be, and with how... tangled Angel is to Shemihaza and the Uzai (shudder), it seems to me that the Paladins also need to be somehow contracted/bound to one of the Grigori or Mephisto.
I think they have to have made a deal at some point that basically makes it where they have to be obedient to the Grigori/Mephisto (I think this specifically applies to Shemihaza more than Azazel or Armumahel as we've seen Shemihaza be the most active of the three Grigori.)
In my opinion, that knocks Yukio out. At least so far. He's been clever enough and careful enough with his words to not entangle himself in a deal/bargain/promise with any of the demon kings or Sol, at least that we've seen yet.
Rin on the other hand...
Rin hasn't always been so careful around a certain Demon King of Time and Space who has owned at least two of the last three Paladins.
I don't think Rin would qualify in a standard and fair test of all the Orders. He doesn't have the strategic mind or the understanding of demons to properly hold the role and there would be other more qualified candidates unless he has some pretty big personality changes towards learning those things.
However, as far as having to be the dog of someone and serve the Order, yeah. Of the twins, Rin is the one that would get himself in a deal, and I think he already has.
But yeah, the whole promotion to Paladin has been pretty secretive so far with Shirou giving us a glimpse of the ceremony, but not really of the criteria for why he was picked, other than that he made the mistake of agreeing to be Mephisto's dog if he succumbed to a demon.
