Now that Guild Wars Live team have deployed the 'whole hero team' update, are there any strategies for beating Shiro using a whole hero party?
I've managed to figure this out in the end, it involved allowing Koss and Goren to tank, and then using 'Pain Inverter' on Shiro when he activated Impossible Odds.
Victory! I've included the shot for skill reference and team makeup.
Along with pain inverter, one skill that makes killing shiro extremely easy (even on HM for masters), is Spoil Victor.
Put this on him while he goes into impossible odds mode, and he will quickly kill himself as he takes out his target. On top of that, bring along a second curse necro and apply Spiteful Spirit and he will drop in no time.
Some general strategies: Use your celestial skill to kill any shiroken spawned by banished team members/henchmen to bring them back faster. Also, the kill will give you a morale boost and recharge your celestial skill. Note, if you are taking all heroes then you will not be banished as heroes cannot be banished and Shiro will not banish you if you are the only player.
Bring along a high damage skill when he goes into meditation of the reaper to knock him out of it faster. The longer he stays in that pose the more damage you will take when he exits the pose.
Finally, keep in mind that impossible odds removes all hexes from Shiro so wait to cast the hexes on him until after he activates the skill.