Here there Be Dragons: Aži Dahāka, 3.5/Pathfinder

Here is a stab at Liam's big dragon, Aži Dahāka.  I used a couple of different tools and then manually tweaked them.

More details on his monster here soon.  Right now I want to know how these stats look to you.

Aži Dahāka
Dragon, Great Wyrm Fiendish
CR 28 XP 3,100,000
Chaotic evil Colossal Dragon
Init +4; Senses Blindsense, Darkvision 60; Listen +53; Spot +53

DEFENSE
AC 41, Touch 2, flat footed 41 (+ No Armour, + Shield, none)
(+39 Natural, -8 size)
hp 660 (40d12+400);
Fort +32, Ref +22, Will +32
Damage reduction 20/magic, Immunity to fire, Spell Resistance 32, Resistance to cold and fire 10

OFFENSE
Speed 40, fly 200ft.
Melee
Single Attack Bite +50 (4d8+17)
Full Attack
Bite +50 (4d8+17)
2 Claw +47 (4d6+8)
Crush +47 (4d8+8)
Tail +47 (4d6+8)
2 Wing Slap +47 (2d8+8)
Space 30ft.; Reach 20ft.
Special Attacks
Breath Weapon DC(40) 24d10 Fire 60ft cone, Frightful Presence DC(38) , Sorcerer 19,
Spell-like Abilities Sorcerer level 19,
Smite good 1 per day add extra damage = to HD total

Spell-like Abilities
Spell-like Abilities (CHR) 3rd DC(21) Locate object 11/day
Spell-like Abilities (CHR) 3rd DC(21) Suggestion 3/day
Spell-like Abilities (CHR) 6th DC(24) Find the path 1/day
Spell-like Abilities (CHR) 8th DC(26) Discern location 1/day

Spells Known:

Spells  (will choose these later)
Level 0 (6) DC 18
Level 1 (8) DC 19
Level 2 (8) DC 20
Level 3 (8) DC 21
Level 4 (8) DC 22
Level 5 (7) DC 23
Level 6 (7) DC 24
Level 7 (7) DC 25
Level 8 (7) DC 26
Level 9 (4) DC 27

STATISTICS
Str 45, Dex 10, Con 31, Int 26, Wis 27, Chr 26
Base Attack 40 Grapple 73
Feats
Alertness: +2 listen +2 spot,
Blind-fight: Re-roll miss chance for concealment,
Cleave: Get extra attack if kill monster,
Flyby Attack: Can make standard action during move,
Great Cleave: Can make extra attacks if kill opponent ,
Hover: Can Hover,
Improved Initiative: +4 Initiative checks,
Iron Will: +2 on will saves,
Multiattack: Secondary Attacks are at -2 instead of -5,
Power Attack: Subtract from to hit add to damage,
Snatch: Snatch prey in mouth or claw,
Weapon Focus: +1 to attack rolls,
Widen Spell,
Wingover: Can change directions quickly while flying
Skills Appraise 28, Bluff 44, Concentration 46, Diplomacy 51, Hide 14, Intimidate 49, Know Arcana 41, Know Geography 41, Know History 41, Know Local 41, Know Nobility 47, Knowledge (any one) 41, Listen 53, Move Silently 39, Search 51, Spot 53, Swim 47
Languages Abyssal, Aquan, Common, Draconic, Infernal, Undercommon

ECOLOGY
Environment Deserts
Organization Unique
Treasure Standard x 3