I play favorites. It's a fact. We all do. We all have things or people we like so we give them varying degrees of slack or focus.
Looking at my campaign world, it's easy to see that I play favorites. There are certain races and nations that I like more than the others. So their background material is more fleshed out (extremely so in some cases), and they feature heavily as the focus or environment of my plots and quests. The side effect of this is that I am far more resistant to that whole "burning the world down around them" aspect of players interacting with my favorite race/nation/etc. I mean fine, the players want to burn down The Plains of Dust? By all means. Oh, you want to melt Steeltown into slag and sell it to a scrap yeard? Uh, yeah, here's sixty reasons that is going to be hard and complicated and you'll die. I made up forty of them three seconds ago. Also, there's a flaming comet circling the planet with your name on it with a proximity sensor near the border of Steeltown.
Jason recently did some stuff and got some powers. He suggested that I maybe create a similar situation so as to give the other guys access to powers and not be guilty of favoritism. There is a certain amount of merit to what he said, this is a game and I like everyone to be fairly equal in power. Even if people miss sessions or are late or leave early or don't pay attention to shit. Additionally, the rules kind of imply that I, as the GM, am supposed to be an impartial arbiter of the rules that crafts scenarios to progress them along their goals while keeping things fair and balanced.
My job, as it relates to them, is to make the scenarios, make their actions and choices have consequences (for good or ill), and to distribute xp and loot to them evenly. Everything else is on them. They want to mess with things they can't handle, it's my job to warn them off somehow. If they persist, it's on them. If they need important information, it's my job to tell them that important information or give them access to it and their job to write it down if they get it. If there is a weakness they need to exploit that will make an enemy vulnerable, it's my job to give them a chance to find it. Etc, etc, etc. GMs are not baby sitters and hand holders and wipe your butt and tell you that your special-ers, and even if they're supposed to be, I have no desire to be one.
Jason/Karrak made specific choices that led to him absorbing a piece of the Hound's Gifts when it died, choices that any other character in the group could have made, but did not. Eran made specific choices to make a deal with the Hound to obtain power (then reneged on it in the Hound's eyes, resulting in consequences that affected everyone, or at least Gob and Karrak), then made further specific choices (not apologizing for forgetting about the creature on the Black Mountain) that prevented Evandor from rewarding the group (with his Gifts, so they could all gank power from dying Immortals) for in part being responsible for reuniting Andorian and Evandor.
To me, giving Karrak access to these powers or allowing Eran to make deals with supernatural creatures is not favoritism. These options are present in the world, the same way a player has the option of choosing to play a Psion, Wizard, or Fighter. They merely have to make the choice to pursue these options. Now, each of these choices has consequences. Wizards lack hit points, Fighters lack the ability to affect reality with their sorcery, Psions...uh...make pretty lights and funny noises that are somewhat alarming when they manifest their powers (sometimes, if they don't decide to suppress them)?
Man, psionics are fucking powerful.
These are options, like selecting feats and abilities. Jason, to me, kind of chose the feat "Make Me Immortal" which had the prerequisite of "Have a Nel owe you a favor" or "cast wish" and then chose the feat "Absorb the Hound's Gifts" because he met the prerequisite of "Possess Gifts" and wanted more power. It would be no different that Eran choosing to pursue the Hound's mission statement of hunting all of the things and gaining a lycanthrope template or something. That was the eventual plan, Lance. Plus whatever you wanted to do with the whole Inquisitor archetype I devised for you. Sorry. The Hound has no use for riflemen or hunters committed to keeping the demons out of the overworld and would have reshaped you in his image, because he is the alpha and Eran was not. Eran would have become a were-nyeklaeon and would have constantly struggled (through RP and Will saves) to maintain his Serethmanity. Which is humanity, but for Sereth.
Maybe I'm off base here. But giving Karrak or Eran power that Karl and Donovan don't have doesn't feel like favoritism to me. Karl and Donovan have those sames options as well, they've just chosen not to pursue them. The same way everyone has followers, but Eran/Lance has not chosen to take Leadership. I might not have flat out said it to everyone, but I've shown that this land has the Immortals, and some Immortals have followers and reward them with powers. I cite the priests of the Armiger and the Houndlings of Cantellen and the various weirdly powerful and intelligent canines of Orcunraytrel as examples. Eran/Lance decided to try to strike a bargain with one of these Immortals for power. Anyone could have.
I don't feel like I'm obligated to give powers comparable to Karrak's to everyone just because it's fair. That's like saying every time I hand out magic loot (granted, this is rare, but wolves and common rank and file soldiers tend to not have piles of magic on them), I should give out four sets of the same stuff. I think I am fair and balanced, in that everyone has the option of finding an Immortal and serving them for power. Everyone in the group has the option of taking money and going to the Goebleen to buy magic gear their Witches create. Everyone has the option of calling everyone else out if they feel they did something stupid or selfish with the money. What would have been unfair was if they freed Andorian and he only gave his boon to Eran because he was a Sereth, or if I said Eran was the only one who could have absorbed the Gifts of Immortals because he was Sereth.
I dunno, just something that I felt like yammering about.