I killed 4-2's Ouryu in a 5-person party of me (DRK/WAR), BLU/THF, and BLMx3.
Tank, you ask? Well, there was no real tank...I just happened to spam voke, bind, stun, and absorb/Aspir enough while Ouryu was slept that I held hate off of 3 volleys of Freeze x3 and Sleep.
So, the good news is DRK/WAR can easily hold hate off of spammed ancient magic (and I didn't use LR or SE to grab hate, nor could I use Sleep for hate for fear of Ouryu building a resistance). The bad news is, Ouryu hits you for 200 dmg. a pop, and you can only "tank" him if he's being slept in between volleys.
Was Ouryu one of the ones they nerfed? I'm not sure if it was meant to be beaten fairly easily with 5 people...
No, it's too late. Already, great cataracts of blood pour forth in mighty rivulets of gore from the vicious, millimeter-deep wounds I have dealt to my forearm with my Vorpal Safety Pin of Weeping.