Help Needed: Manyshot and Deflect Arrow

[MiB]

What's the correct way to handle the following situation:
A character with the Deflect Arrows feat is attacked by a character using the Manyshot feat. The archer scores a hit. How much damage does the target take?
Technically, you can deflect one attack from a ranged weapon per round. The Manyshot uses only one attack roll. Is it considered a single attack which is completely deflected, or is each arrow counted as an attack, so you can deflect only one of them?

What happens in case of critical hit (which applies only to the first arrow in the volley). Can you deflect this one arrow? All of them? Or just a standard one and take the rest of them, including the crit?

 

[Korak]

Technically, you can deflect one attack from a ranged weapon per round.

Not exactly.

. Once per round when you would normally be hit with a ranged weapon, you may deflect it so that you take no damage from it. You must be aware of the attack and not flatfooted.

Deflect Arrows negates one hit, not one attack. The manyshot action allows up to 4 hits from a single attack. A creature with deflect arrows can negate one of the projectiles. Any of them can be negated, but only one. However, since precision and critical damage can only be applied to the "first" hit, it would be smart to deflect that one.