Oberyn
Forceful, lusty, hot tempered, passionate, grudge holding, overconfident, loyal to those he cares about.Switches between being laid-back and easygoing to being serious.
All this points to SEE.
I considered EIE-Fe, but his Se is very strong, I don't recall him demonstrating Ni, and he doesn't respect authority.
Thus he's SEE-Se.



Brienne
IJ temperament is obvious. SLI? No. She's judgemental, strict and stable, and doesn't actually explicitly demonstrate Si, or even Te.
I lean LSI > ESI.
She's awkward, yearns for acceptance, and she uses Ti over Fi.
It may seem that her deep loyalty to individuals and not their groups points to Fi, but in fact, Brienne is just adhering to the expectations and guidelines of knighthood, when no one else does.
She found a system of behaviour she likes and strives to adhere to it completely, to the point of ignoring efficiency [Te ignoring].
LSI-Se.



Roose Bolton
Obvious Gamma NT.
He's cautious, calm, calculating, politically atute, coldly realistic and a cunning strategist.
He never publicly expresses anger, happiness, or sadness.
He offers the most pragmatic advice to Robb Stark, albeit the most ruthless.
For all his caution while dealing with his enemies, Roose ironically fails to see the threat right in front of him i.e Ramsay [weak Fi].
His calmness points towards ILI, Te subtype.



Varys
Calm and reserved demeanour.
Able to wade through one confrontation after another without losing his dignity, temper or advantage.
Speaks in riddles.
Appears meek, subservient and passive, but is a master of deception, manipulation and calculation.
This points to ILI or IEI.
While he seems good at Fe, it's all very over the top and pretty laughable. I [ILI] could do the same in his situation.
He's good at Te, see him when he's ruling Meereen with Tyrion.
More importantly, he seems Fi valuing.
He develops close emotional connections with people and has a vengeful Gamma-ish nature [the sorcerer].
ILI are also better at Se than IEI in my experience, which Varys occasionally demonstrates.
So ILI-Ni. This subtype explains his somewhat strong ethics.



Renly Baratheon
Obvious ethical extrovert.
Uneasy around violence and blood, According to him, all he heard about from Robert was how he was never "tough" enough.
This leaves ESE and IEE.
He's skilled in politics and was patient, pointing to IEE.
He also relied on his charisma and popularity for the support of his troops rather than propaganda, which is habitual of Fi creatives.
Conflicts with Stannis.
He's IEE-Fi.