Its Armor Class should be touch 13, flat-footed 10, not vica-versa.
Do we want to include any of this:
In its diminutive state, the sawfly can dodge any attack if it makes a successful saving throw vs. wands. However, any successful hit crushes it. It cannot attack in small form.
That suggests rewriting the Change Size SQ. How's this.
Reduce Size (Su): As a standard action, a demonic sawfly can magically reduce itself to Fine size. The demonic sawfly can remain in Fine size for as long as it wishes and it can return to normal size as a swift action. While Fine-sized, a demonic sawfly loses its natural attack, but gains an ability to evade its enemies' attacks. It has the following statistics:
Demonic Sawfly, Reduced
Fine Magical Beast (Extraplanar)
Hit Dice: 2d10 (11 hp)
Initiative: +3
Speed: 30 ft. (6 squares), fly 30 ft. (good)
Armor Class: 21 (+8 size, +3 Dex), touch 21, flat-footed 18
Base Attack/Grapple: +2/-19
Attack: —
Full Attack: —
Space/Reach: ½ ft./0 ft.
Special Attacks: Change size, masquerade, summon gnat swarm
Special Qualities: Darkvision 60 ft., evade attacks, improved evasion, low-light vision, scent
Saves: Fort +3, Ref +6, Will +1
Abilities: Str 1, Dex 17, Con 11, Int 4, Wis 12, Cha 10
Evade Attacks (Ex): Anytime a Fine-size demonic sawfly would be hit by a weapon attack, it may attempt to dodge the blow. If if succeeds at a Reflex save (including a +4 size bonus, for Ref +10) against a DC equal to the attack roll of its opponent, the sawfly dodges the weapon attack and takes no damage.
A Fine-sized demonic sawfly can also evade magical and unusual attacks that normally deals half damage on a successful Reflex saving throw. If the demonic sawfly makes a successful Reflex saving throw (Ref +10, including a +4 size bonus) against such an attack it takes no damage, it takes only half damage on a failed save.
A helpless demonic sawfly, or one with medium or heavy encumbrance, can not use evade attacks.
