For this exploit you will need a warlock with an ornate spyglass and possibly a soulstone I haven't confirmed if this works with any other pet. Obviously you will also need a group capable of killing the black stalk (hopefully in one attempt)
Zone into heroic UB with your group. Kill the first few mobs and go to the top left corner of the wall in the first little halway immediately after the first pull. Have your whole group stand of top of each other and have the warlock have his imp out. Look into that wall with a engineer scope (to look into the distance) while spaming /target black stalker until he patrols close enough for you to target him. then with that have the lock spam the imps fireball attack, since the imp is tricked into thinking you're closer to the mob then you really are since the lock is using the ornate spyglass.
As soon as the imp casts a fireball, your warlock will get into combat. At this point have your whole team also try to get into combat by spaming battleshout and possibly auto attack. When your group gets into combat, one by one when the black stalker targets one of your teammates they will be ported to him from the beginning of the instance, since the black stalker is actually right next to the enterance. It's a bug so it doesnt always work, but most of the time I could get 3 people across including the lock. When you enter combat with the black stalker, you automatically port to his room. You can try to run away out of the room to reset, but that might stop your teammates from getting ported for some reason, in my experience anyway. it's best just to die and have a soulstone on the healer. when the group wipes, you can have the soulstoned healer pop up and res the group. Summon anyone who didnt make it and buff up to kill this boss. After you kill the black stalker, you can turn around and kill that hunter boss for an easy 2nd heroic token.
Congrats, you killed the last 2 bosses in a heroic instance and only had to do one trash pull. You can do this every day when the heroic resets.
Thx to snarg