Warning: This is 3.0 Edition material. It is possible that there is more recent 3.5 Edition version.
Inaccurate?

Improved Death Attack

( Epic Level Handbook, p. 58)

[Epic]

Prerequisite

Death attack class feature, sneak attack +5d6,

Benefit

Add +2 to the DC of your death attack.

Special

This feat may be taken multiple times. Its effects stack.