Epic Whispers of Death

From publisher blurb:

The new edition of the core rulebooks gives information on advancing characters beyond 20th level. This document provides the epic level progressions for three of the 10 level prestige classes from the Whispers of Death: A Sourcebook for Assassin Characters book: Shadowblade, Slayer, and Sniper. Characters must be at least 20th level to advance to 11th level in any of these prestige classes. Each class improves on its previous abilities, but gains no new abilities. Some abilities hit maximum power at or before 10th level and do not increase in power after 10th level. In addition to enhancing previous abilities, all epic assassins receive bonus feats as noted on each epic progression.