I made the following stats for a typical soldier in the Hellknight Order of the Nail.
I made the Hellknight soldier based on the Hellknight prestige class (from The Inner Sea World Guide), the Guide to Korvosa (which has Hellknights listed as level 4 fighters), the elite array, and my rules for prestige classes (basically I allow them much sooner than normal, as long as the prerequisites are fulfilled asap).
So here it is.
Hellknight (Order of the Nail) CR3
Male/female human hellknight 3; fighter 1
LN Medium humanoid
Init +1; Senses Perception -1
DEFENSE
AC 20, touch 11, flat-footed 19
(+9 armor, +1 Dex)
hp 33 (4d10+7) (Max= 47)
Fort +5, Ref +2, Will +0; +2 vs compulsion
OFFENSE
Speed 30 ft.
Melee mwk greatsword +8 (2d6+12/19–20)
Special Attacks smite chaos 1/day (+2 attack and AC, +3 damage)
Hellknight Spell-Like Abilities (CL 3rd; concentration +5)
At will—detect chaos
discern lies (5 times per day)
TACTICS
During Combat The Hellknights focus their melee attacks on one opponent until he is defeated.
STATISTICS
Str 18, Dex 12, Con 13, Int 10, Wis 8, Cha 14
Base Atk +4; CMB +8; CMD 19
Feats Dazzling Display, Gory Finish, Power Attack, Weapon Focus
Skills Intimidate +9, Knowledge (local) +4, Knowledge (planes) +5, Linguistics +1, Perception +3, Ride +5, Sense Motive +3, Survival +3
Languages Common, Infernal
SQ aura of law, hellknight armor, force of will (compulsion), order of the nail
Combat Gear holy water; Other Gear Hellknight armor, masterwork greatsword, 25 gp
SPECIAL ABILITIES
Onslaught: Once per day as a free action, a Hellknight's base speed is increased by +10 feet and gains a +4 bonus to Strength for 1 round per Hellknight level.
Gory Finish: If you use an attack action (standard action) to make an attack and the attack reduces your target to 0 hp or less, make a free intimidate check for everyone in 30' to demoralize.