Needs review
Source: Epic Level Handbook

Description: Choose one type of melee weapon, such as longsword or greataxe. With that weapon, you do more damage on a critical hit.

Prerequisites: Cleave, Power Attack, Epic Level, Weapon Focus, Improved Critical, Great Cleave, STR 23

Required for: Devastating Critical

When using the weapon, you have selected, you deal an extra 1d6 points of damage on a successful critical hit. If the weapon's critical multiplier is times 3, add an extra 2d6 points of damage instead, and if the multiplier is 4, add an extra 3d6 points of damage instead. (Creatures immune to critical hits can't be affected by this feat.)

Special

You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of weapon.