We do the ignore Shiro trick, works every time. I'm sure some will lol, but we always take an mm hero/person. Minions distract Shiro VERY well while we cap the shrines. Then we run out the door again.
I had guild groups for most of my chars but decided to go for masters with only heroes/henches on my sin, and it was very easy (before the hm/normal mode nerf). The trick there, is A/W with Mark of Insecurity and Wild Blow. Never seen Shiro go down so fast.
Anyway, just another idea.