Mythic+ Tips and Tricks
What you need for most of these tips are fairly simple. Yypically the most complicated thing on this list is having a Venthyr in Halls of Atonement. There are some positional things such as tagging stoneborns over walls, but that is on a case by case basis.
Using Loyal Stoneborns in Halls of Atonement
For basic Loyal Stoneborn management, the general rule of thumb is to use the Loyal Stoneborn on single target encounters or Prideful as the value is significantly diminished on AOE. With this in mind, you should design a route that will pull massive on AOE, use offensive cds on that, and then use the Loyal Stoneborn in the downtime to kill off mobs such as the Prideful, pull bosses, or even Shard of Halkias.
Tip #1: Double Stoneborn
One thing that is important to note is that you are not normally able to mind control 2 Loyal Stoneborns at once. However, under certain circumstances you are able to mind control 2 at once — the stoneborns need to be stacked and you need to chain spam your Extra Action Button. This will allow you to queue up your cast for the Mind Control on the second Stoneborn and control them both.
Tip #2: Unconventional Pulls
There is one Loyal Stoneborn that you can pull over the wall into the Halkias courtyard. You do this by pulling or CCing the trash surrounding the area involved and pulling the stoneborn through. You can see that demonstrated in the clip below.
Tip #3: Stoneborn into Inquisitor Sigar
Stoneborns can be snapped and pulled into the Inquisitor Sigar mini boss. This can allow you to phase this miniboss incredibly quickly and forego killing the adds entirely. This tactic is done by mind controlling the Inquisitor Sigar right before your team fully walks through the mirror and then the Inquisitor Sigar will come with you to the next area!
You can see that done by clicking here.
Tip #4 Raging Stoneborns
Stoneborns are also affected by the Raging and if they are mind controlled once they reach the raging threshold then the Inquisitor Sigar will maintain the Raging on them, which will cause them to do tremendous amounts of damage. In addition to that, the Inquisitor Sigar are affected by haste pretty heavily, so things such as Power Infusion can also be very lucrative to use on the stoneborns if you are pushing a key high enough.
When to Try These Tricks
All of these tactics are practical in weekly keys and normal runs. Feel free to implement them as you see fit, and use them very often as they can save you significant time! GL and get that IO :).