I found BM to be trivial even without using any devices. Group makeup is tankadin, holydin, 3xmage. Tankadin makes holding aoe agro simple. Mages burn down the rift lords. Holydin keeps the tank alive. The first two bosses are simple tank and spank. The third boss is also simple tank and spank just point him away from group.

The hardest mobs are the caster rift lords/keepers. The ice one likes to cast pyroblast at mages so make sure to keep them topped off. There is another one that fears and casts aoe bolt volley.

Keep the party alive in between bosses and do not get behind (drink to full after every keeper/lord you have the time). The most difficult part of the instance is the "combat bug" where you remain in combat and cannot drink after combat ends for 10-20 seconds. In that case I use the device to clean up near the Khadagar and head straight for new portal.

Ziran