Here are the hoary hunter and his steed. As with the gloom, I ran into the problem of them having far too many HD for their size/type. I think, though, that the designers gave them a crapload of class levels that somehow translated over to racial HD (not sure how that works, though). The gloom would thus be a monstrous humanoid with 25 rogue levels and no racial HD; the hoary hunter would have 20+ fighter levels and some racial HD (because fey always have racial HD); I'm thinking somewhere around 4-5 HD, and 30 or so levels of fighter. I could easily revise the stats to reflect that, but I wanted to get some input first.
Hoary Hunter
Medium Fey (Cold)
Hit Dice: 32d6+384 (496 hp)
Initiative: +15
Speed: 30 ft. (6 squares)
Armor Class: 33 (+11 Dex, +4 natural, +8 deflection), touch 29, flat-footed 22
Base Attack/Grapple: +16/+29
Attack: //+6 keen longsword of binding// +27 melee (1d8+19/17-20 plus binding)
Full Attack: //+6 keen longsword of binding// +27/+22/+17 melee (1d8+19/17–20 plus binding)
Space/Reach: 5 ft./5 ft.
Special Attacks: Spell-like abilities
Special Qualities: Cold resistance 25, DR 15/cold iron and magic, fire vulnerability, full SR
Saves: Fort +25, Ref +29, Will +24
Abilities: Str 36, Dex 33, Con 34, Int 21, Wis 23, Cha 26
Skills: Diplomacy +43, Intimidate +43, Knowledge (geography, nature, the planes) +40, Perception +41, Ride +46, Search +40, Sense Motive +41, Stealth +46, Survival +41
Feats: Cleave, Dire Charge, Great Cleave, Improved Critical (longsword), Improved Initiative, Mounted Combat, Ride-By Attack, Spirited Charge, Superior Initiative, Track, Trample, Weapon Focus (longsword)
Environment: Any cold
Organization: Solitary or company (2–5)
ECL: ??
Treasure: None
Alignment: Always neutral evil
Advancement: By character class
A hoary hunter's natural weapons are treated as cold iron and magical for the purpose of overcoming damage reduction.
Combat
A critical hit (or the blow that would kill or render a foe unconscious) from the hoary hunter's blade does not wound the hunter's prey. Instead, the victim is bodily transported as per a //trap the soul// spell heightened to 16th level (DC 30) into a diamond in the sword's hilt.
Spell-Like Abilities: At will — //discern location, true strike, fog cloud, hold monster, plane shift//; 3/day — //dimensional anchor, dominate monster, greater dispel magic//; 1/day — //disjunction, contingent recall and resurrection//*. Caster level 23rd; save DC 18 + spell level. *//Contingent recall and resurrection// is a variation on an epic spell. When slain, the hoary hunter is actually transported, with its mount, back to the fey realm, where it is resurrected. The only way to truly slay the hoary hunter is to defeat it in its home realm after this epic spell has been exhausted for the day.
Hoary Steed
Large Magical Beast (Cold)
Hit Dice: 12d10+36 (102 hp)
Initiative: +8
Speed: 40 ft. (8 squares), fly 90 ft. (16 squares) (good)
Armor Class: 21 (–1 size, +4 Dex, +8 natural), touch 13, flat-footed 17
Base Attack/Grapple: +12/+19
Attack: Hoof +17 melee (1d8+6)
Full Attack: 2 hooves +17 melee (1d8+6) and bite +15 melee (1d6+3)
Space/Reach: 10 ft./5 ft.
Special Attacks: --
Special Qualities: Air walk, astral projection and etherealness, cold resistance 15, DR 5/cold iron and magic, fire vulnerability, immunities, magic circle against good, misty breath, moderate SR
Saves: Fort +11, Ref +12, Will +5
Abilities: Str 22, Dex 18, Con 17, Int 6, Wis 12, Cha 12
Skills: Jump +12, Perception +7
Feats: Endurance, Flyby Attack, Improved Initiative, Multiattack, Run
Environment: Any cold
Organization: Solitary (with rider)
ECL: ??
Treasure: None
Alignment: Always neutral evil
Advancement: 13–16 HD (Large); 17–36 HD (Huge)
A hoary steed's natural weapons are treated as cold iron and magic for the purpose of overcoming damage reduction.
Combat
Air Walk (Su): A hoary steed can ride through the air as well as on the ground, as though affected by a permanent air walk spell.
Astral Projection and Etherealness (Su): These abilities function just like the spells of the same names as cast by a 20th-level caster.
Immunities (Ex): A hoary steed is immune to all charm and hold spells or abilities.
Magic Circle Against Good (Su): This ability continuously duplicates the effects of the spell. A hoary steed cannot suppress this ability.
Misty Breath (Su): The breath of a hoary steed functions like a constant obscuring mist spell.