Filial is the name of the second part of the final boss in Armored Core 2.
The Filial was a Disorder Unit designed by the ancient Martian race that previously inhabited Mars and was used by Leos Klein in the Phobos moon against the Raven. The unit was revealed as the Raven destroyed the Scarabaeus, revealing this smaller and slimmer model inside. In this form, the weapon gains greatly in mobility, and deploys orbit cannons while utilizing two MOONLIGHT equivalent blades and what appears to be an energy shotgun mounted on the head. The unit is also capable of using over boost. It is eventually defeated by the Raven and destroyed as Phobos burned up upon reentry into Mars' atmosphere. In order to lock on to this unit you need a bio sensor.
- Dual Laser Blade
- Orbit Cannon
- Energy Shotgun
Filial is quite a powerful enemy, although nowhere near as powerful as other bosses in the series like IBIS or Nine Ball Seraph. It is fairly nasty and ultimately is quite quick, especially its energy shotgun; it can cause some stun. One recommended way of fighting him (and indeed the recommended strategy for most of the later missions) is to use a quad leg or hover leg AC with a high powered arm weapon. These could be the arm cannons like the Grenade Cannon or it could be the KARASAWA laser rifle. After defeating Klien's first form, your AP and ammo are replenished. This form takes an high amount of damage, even with the KARASAWA or heavy weapons. The speed of the legs is required to keep up with him and it's best to stay close to him, although not too close as to avoid his laser blades. Ultimately he can be defeated easily enough with hard hitting weapons.
The unit only appears in the final mission of Armored Core 2 Phobos.