Improved Sinister Strike is a Rogue talent located in the 1st tier of the Combat Tree that increases damage dealt by and reduces the energy cost of the [Sinister Strike] ability.
Rank Table
Rank
Damage increase
Energy reduction
1
10%
2
2
20%
4
3
30%
6
Notes
To new players, this talent doesn't appear obviously attractive, however, not only does the saving add up over time to more damage per play session, it also can mean that you are generating combo points quicker when you really need them, coming out of zero energy.
Patch changes
Patch 4.0.1 (2010-10-12): Improved Sinister Strike is now a 3 rank talent and also increases damage dealt by Sinister Strike.