where is flashing blades?

can anyone help me?
ive already done helping the gaurds and searched every inch of Shenzun Tunnels and cnat find it anywhere

Use this site

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

Even with a map it isn't easy to find him. He doesn't show on radar. That boss is hiding until you go down the stairs in that area. Then Lou and his minions pop out. Lucky for you there is a res shrine right there.

thanks for your help guys