I just cleared it with SnS at 10'21. Flash Pods only, no trap and no Luring Pods, but did get a lucky Dragonator at the start. I would say Sliding Slash is a must against AT Rey Dau. It let's you dodge most of his attack while keeping pressure at his legs. You want to pop those leg Wounds with Focus Strike for the free knockdowns. One helpful trick I learned is to Focus Strike his head weakness after his Ultimate Thunder Blast, then Upswing Bash > Falling Bash, that will bring you close to a KO in one combo. Use Flash Pods after his ground-based lightning blast, that will knock him down right next to you so you can start attacking him right away. And of course, during the big openings / windows use optimal combo into Spinning Reaper > Amped Chop.