This guide applies to both heroic and normal versions of the encounter. I’m not going to go over the strategy or the abilities in the Dungeon Journal, you can look that up yourself.
For now, here is how you should kite Riplimb to ensure the stacks of Jagged Tear fall off both tanks. Shannox is the represented by the skull, Riplimb is the square, and the spear is the star.
1. Tank Shannox and Riplimb as far apart as possible, which is 80 yards, so that neither one gets Separation Anxiety. Shannox will throw his spear on the ground somewhere near Riplimb. Shannox cannot apply Jagged Tear while his spear is thrown. Riplimb cannot apply Jagged Tear while he is retrieving the spear.
2. Once the red circle that denotes a spear location appears, sprint, leap, or get life gripped far away. It’s preferable to run toward Shannox. Riplimb will follow you until the spear actually lands in the red circle. They key here is that you need to prevent him from re-applying Jagged Tear, so try to stay out of his melee range until he turns away from you (this is why life grip and heroic leap are so good for this fight).
3. Riplimb becomes snarable as soon as he attempts to retrieve the spear. Once he turns away from you, snare him or call for someone else’s snare. Follow him back to the spear to make sure the snare does not fall off. Snares that were applied before he turns away from the tank will not slow him down; they must be applied after this point.
4. Riplimb retrieves the spear, then heads back to Shannox. He is still snareable, so refresh those snares before he turns around. Stay on the far end of the area while he runs away.
5. Shannox gets his spear back and goes back to applying Jagged Tear. Riplimb runs back to you (his main aggro target). His snares might have to be reapplied at this point, but not by you, because you need to kite him.
6. If Jagged Tear hasn’t fallen off yet, you can either try to trap him in a Crystal Prison (but try not to steal one from someone who needs to trap Facerage), or kite him for a few more seconds. If he’s snared and you’re a druid, you can kite him in cat form, though you will very likely die if he gets close enough to hit you. It’s harder to trap him, because he will likely already have the Wary buff from running over Immolation Traps in the middle of the field. If neither is an option, pop a dodge trinket and hope for the best. Even in heroic mode, you can fail to reset your stacks once or twice if you pop a cooldown.
Hopefully your Jagged Tear stacks will fall off by the time Riplimb brings the spear back. If they don’t consistently do so, then you might need to call for a crystal trap on Riplimb or use two tanks on Shannox. If you use two Shannox tanks, they will need to swap threat with clever uses of Tricks, Misdirect, Salvs, and good ol’fashioned stop attack.
You can also ensure stacks get reset by kiting Shannox when Riplimb is trying to return the spear. The Shannox tank should walk backwards while Riplimb is trailing the boss. Walking backwards and keeping Riplimb snared should be fast enough to avoid spear transfer. When both you and the Riplimb tank have their stacks reset, stop kiting.
Here’s a video of me putting all that into action.