The "Ambushing" of Fellstroke should cause +25% sneak attack damage, but the effect is not listed under active effects and does not appear in the combat log, like other sneak attacks. Im afraid that the effect does not work, but it is difficult to test this. So another question: Is it possible to modify a weapon to deal constant damage? That would make it easier.
Edited by Azzinoth224, 29 August 2015 - 05:47 AM.