Where can I cap flashing Blades?

I have looked everywhere for this, and cant find an assasin boss with this skill.

Does anyone know where I can get it?

http://www.xennon.co.uk/eliteskills/Lou.JPG

Head down to the giant red X

The trick is to run down the stairs and up the other side. Some marksmen will descend from out of thin air (there is no roof here, weird). Slaughter them. You may have to run around the hole a couple of times to make sure they all spawn, maybe even descend and ascend the steps once more. The boss will appear and teleport to the bottom of the hole. Kill him and rejoice.

erm, I cant get acess to that picture lol, though it may jus be because of my uni computers. Ill try again l8er though.

Nope, you won't be able to access that link at all cause direct linking is disabled :-)

Just go to http://www.xennon.co.uk/eliteskills/ instead :-)

That page seems to say that you can only cap the skill from two bosses while you're doing the quests they're part of - does anyone know of any other bosses that have it?