Borderlands: Game of the Year Edition
81 Achievements
64-76h
Truly Outrageous
Killed an enemy with the Siren's action skill
34.1%
How to unlock the Truly Outrageous achievement in Borderlands: Game of the Year Edition - Definitive Guide
Once you reach level 5, you will unlock the action skill. Find some low-level enemies outside of Fyrestone (Skags are perfect), take down the health of a few of them by shooting until they only have a small amount of HP, and then press to trigger the skill.
You will need to be level 5 before you can unlock any character's action skill.
The Siren's action skill is unique in how you use it to kill enemies as it's not an offensive skill. You will have to unlock certain skills that will add offensive damage to your action skill. In the Elemental skill tree, the skill 'Radiance' will apply shock damage to nearby enemies while your action skill is active. The damage it does is based on your level and the skill's level.
The best way to approach this achievement is after gaining some levels in this skill, head back to the beginning of the game where the enemies are around level 2-3 and activate your action skill when near one to try and have your Radiance shock damage kill them. Otherwise you can shoot stronger enemies until they are almost dead, then activate your action skill to kill them with the shock damage. Luckily you only need to do this to one enemy.
You will gain access to your action skill when you level up to level 5 and to use it, press . The Siren's action skill is Phasewalk which allows you to run around unnoticed and super fast for a few seconds. Phasewalk has two moves i.e a powerful Melee attack and the resulting Phase Blast will do considerable damage to anyone/anything that gets too close.
Unlike the other action skill trophies you only have to get one kill, not 15. Go to the Skag den outside of Fyrestone and weaken an enemy until it has only a sliver of health left, then hit it with a Melee attack whilst Phasewalking and the subsequent explosion from exiting Phasewalk will kill them. Do note that whilst using Phasewalk, you will not be able to jump or use any weapons other than your default Melee attack.