It makes perfect sense for pinkie to serve nurgle, are all he is a jovial and happy figure, which makes him even more fucked up

@Background Pony #6257  
Milk for the Khorneflakes! Salt for the popKhorne!

@T-storm Berzerker  
Blood for the Blood God! Skulls for the Skull Throne!

@Ashdreg  
@Sharpy1991  
No, Nurglite. Pronounced ‘Nurgle-ite.’ Nurglings are his minor daemons, weaker but more numerous than his lesser Daemons, the Plaguebearers.
 
Personally, I’d like to see them ALL serve Khorne, but failing that… So long as I’m commenting, I may as well throw in my 2¢ on their alignment with the Ruinous Powers.  
AJ’s a generalist, so the Black Legion fits. She probably leans towards Nurgle on account of valuing family and nature, but with no Mark, she technically serves Chaos Undivided, lacking the unnatural toughness of a full Plague Marine for more versatility.  
RD’s impetuous aggression fits the World Eaters, but given her sloth and vanity, I’d peg her as more of a Slaaneshi. Could go either way, I suppose, but the Element of Loyalty being a Traitor Marine is a little weird.  
Pinkie’s earnest friendliness fits Nurgle far better than Slaanesh, so even though they have shared domain over her gluttony and parties, she likely serves the Plaguefather, freeing Rarity to serve the Prince of Excess. Her perfectionism and occasional lapses in composure and temperance make her a neat fit, despite her manipulative tendencies being as Tzeentchian as they are Slaaneshi. As much as I revel in every blow she strikes, I can’t contest that one.  
Twi, if she IS a heretic, is a cut-and-dry follower of Tzeentch. Sorcery and knowledge, with obsession and magical mishaps as side effects? Square pony fits square hole.
 
As for ol’ Butterfry… Her outbursts of rage, as with Rarity’s violent moments, fill me with dark joy, but Malal makes sense, considering her refusal to embrace rage and become a monster. That, or she’s a loyalist Blood Angel successor, perhaps even a Flesh Tearer.

@SigmatheArtist
 
Could be she follows the Outcast God…Malal.
 
Which, actually would explain why she’s not with them pretty well given Malal.

@SigmatheArtist  
Flutts is probably in the clear but about that ‘not getting to her’ bit.

I see that people are discussing allocations, so allow me to explain my choices:  

@40kponyguy  
The element of kindness plus the chaos god of anarchy and (self)destruction. Might work. Won’t be much worse than Discord.

Apparently Flutters missed on Chaos mark sign-ups.

@Solitude  
Guess that’d have to be butterbutt then.  
Seeing as she’s the only one missing here.

@Ashdreg  
I know. Just think it’s funny. Also, Sons of Malice are best chapter.

@Ashdreg  
Nurgling.
 
I wouldn’t mind becoming one. Or even better, a Plague Champion. Or even better, a Great Unclean One.

@Sharpy1991  
unless you’re also a…nurgler? Nugleite?

@Ashdreg  
True.
 
He just wants to give you a hug. Too bad you die in the process.

@Sharpy1991  
However, Nurgle is all about family, much like Applejack.
 
Then again, we could argue this ad nauseam.

@Solitude  
Malal…well…GW does not exactly own the rights to him. Kinda hilarious though XD. However, GW does at times do indirect references to him, but not very often.

Now we just need one for Malal.

@T-storm Berzerker  
Best pony? Yes.
 
Best chaos god? I’ll have to disagree. I prefer Nurgle. He loves everyone….except for Tzeentch.XD Too bad Slaanesh is left out.

@Kharn The Generally Swell Guy  
Amen to that, bruva!

Pinkie fits as Plague Marine. She does love everyone, like Nurgle.

@T-storm Berzerker  
I have absolutely no issue with that statement, whatsoever.

Dashie as a khorne ’zerker. I approve of best pony leagued with best chaos god!

Applejack for Chaos Undivided? Personally I think she’d fit better with Nurgle than Pinkie Pie.