[Shadbase]

I'm sure if there are any other logical reasons why not to do this beyond "the grind would be so hard!" you have it would be rather helpful to Jam! Because at this point you've sort-of created this negative bubble of being stubborn and not really adding anything beyond complaining, not to sound purposefully rude, and that's not the point of Suggestion threads.
"This is hard to get so it's not allowed to be countered to this level" is an ice-cold take.

I've given it some thought myself, and even as a supporter I could understand why someone who rides on mostly PVP meta on their spirits would be quite peeved about it, but I believe there are good suggestions that could be done otherwise, but rather a good section of people have just been dragging the thought, which is really sad.

For clarity, here are what others have suggested:

(Balance) (Lolzy) When a spirit adds another point unto a skill, it increases that skill's cooldown by 2.
(Balance) (Shujin) +3 hit per White Spirit on target, +3 crit per Black Spirit on target
(Trait) (Kunai / Pyro) Soul Guide - If you defeat an enemy who is a Ghost, Possessed or Undead, you will reap some of their essence and restore HP/FP equal to Character LV * X (2 + 1 per 1 Spirit).

And that's it. Those're the actual suggestions from those who've disagreed with the trait, and 2/3 are actually just Balance-Fu fodder.

Nobody has been saying at all that the grind for spirits is easy. I use spirits for RP purposes, and I can see exactly how hard they are to get - especially in Korvara, where I barely see any. There are two things that they have been saying:

1) Spirits have absolutely no actual consequences beyond a slight debuff if someone is using a Holy weapon, which is often times a weapon in someone's item belt than something actually being used. Beyond that, you are getting a buff where the only cost is the patience to get them, and then once you're set you have what are basically permanent buffs.

2) There is no real functional reason to play a Reaper or Apertaurus. Reaper especially, since at least Apertaurus have their little hoovsies. Everything a Reaper can do every other race can do better. We have an actual item in-game that even gives you their racial active ability now too.

The point here is effectively "yes, Reapers/Apertaurus have no real abilities that make them a threat and spirit users are basically able to get away with using spirits mechanically for free, here's a thought that would put some risk into that and create RP opportunities". Jam isn't out to get your meta PVP build.

The best criticism against the trait is just that it would make the Amalgama trait, and dog collars, effectively useless - a race specific trait, and an accessory slot you have to sacrifice for. I think that yes, these things should be immune to Jam's initially proposed trait, because it entirely invalidates those things that're made to keep you from losing those. And then look! You have a viable way to keep your little darling spirits against a Reaper/Apertaurus, just swap one of your accessories. It's not really against the rules - just kinda a "are you for real" moment, just roleplay slapping on your collar.
And again, I mentioned it before and I could understand if it would get lost, but it's a viable option as well to simply not get into a PVP fight with a Reaper/Apertaurus. Nobody can force you into PVP, it's actually against the rules - and it's exactly what a few people have been asking for. "Just RP it, you can ICly release your spirits and not mechanically do it". A trait like Jam is suggesting is specifically a punish for people who solve all of their problems through PVP and cannot RP their way out of it.

If anything, Reaper/Apertaurus deserve a trait that actually makes them threatening against spirit-users, because it's practically exactly what they come up from Lazarus to combat most of the time. People who take spirits and use them for their own gain instead of letting them pass on. Even if it's not what Jam suggested to a T, Jam is on the right track of trying to make spirit use something that actually comes with a real risk that people could run into, as well as making an actual reason to play a Reaper/Apertaurus and have something to show for it other than purely IC flavor. Because it's very clear that Soul Guide + Ghost Killer/Scripture is not making anybody consider it.