You need hardly any time at all to study your targets before making a death attack.
Benefit: You need only study your victims for 1 round before being able to make a death attack against them. If you do not launch the attack within 4 rounds of completing the study, 1 new round of study is required. You may increase the DC of the saving throw to resist the death attack by 1 for each additional round you choose to study your opponent, to a maximum of +2 from 3 total rounds of study.
Undefeatable: The Collected Feats Sourcebook, Copyright 2009 – 2010, Louis Porter Jr. Design, Inc. Undefeated, Copyright 2011, Louis Porter Jr. Design, Inc.