Supreme Many Shot
From D&D Wiki
Supreme Many Shot [ranged feats]
Your ability to shoot a handful of arrows at once is now ridiculous
Prerequisite: Manyshot, Greater Manyshot, Point blank shot, Rapid shot, Dex 21, BAB +8
Benefit: When using Manyshot you may now make iterative attacks, each extra arrow added to your normal attacks adds -5 to the hit roll of that attack. If you have a BAB of 16, your 4 attacks would be +1(4 arrows)/+1(3 arrows)/+1(2 arrows)/+1(1 arrow) instead of +16/+11/+6/+1 (1 arrow each).
Normal: Normally you can not make iterative attacks as Manyshot is a standard action and Manyshot usually is a -2 for each arrow fired.
Special: When using this feat with Manyshot with a full attack it replaces the negatives that Manyshot usually gives.