Sorry for the long delay, everybody. Here's an actually interesting monster to make up for it!
The arrow demon is a 10 RHD outsider which unsurprisingly has the Evil and Chaotic subtypes. Its ability scores are quite high in spite of its Medium size, with stellar constitution, good physical stats, and okay mental ones.
Like all demons, they have some random abilities like DR (overcome by cold iron and good), energy resistance, SR 18, Telepathy, and natural armor.
Unlike most demons, they lack a wide range of SLAs, with their only one being at-will, self-only Dimension Door. Not without purpose, but unlikely to make a large impact on the game.
Other special abilities include Wield Oversized Weapon (only applies to bows, sadly), the ability to make AoOs with bows, and not provoke AoOs when using them. It can also summon demons: the two options are a handful of dretches, or another arrow demon that doesn't appear 65% of the time.
Lastly is Symmetrical Archery, which is quite amazing. With it, arrow demons can fire two arrows whenever it'd attack once, with the only downside being a -2 penalty on all attack rolls. It should be obvious that this trait is highly powerful.
Considering the arrow demon's great special abilities, good RHD, and high stats, I think +1 LA can be justified here, even though archery isn't that great a fighting style.