Since it’s the top search landing people here… might as well.
The giant skeletons are trivial to tank. They have a spell reflect that gets hilarious when you have an arcane mage in your group that’s a little too hasty about casting those purple magic missiles. This is much less amusing if you’re the healer.
For the first caster group on the hill, wait until the patrolling Bonecaster pulls up level with the stationary mob closest to you, then whang them both with Avenger’s Shield, then whack the other two with Hammer. As long as you manage to get two for the first throw, the rest of the pack are fairly easy to round up and AOE-tank. Apply this tactic to the other group later on with a patroller; this will be your only chance to actually hit more than one target with your shield during the caster pulls.
The groups of casters that are arranged in a five-point pattern are distanced so that it’s impossible to smack more than one target with your shield on the initial pull. Get the Adept if one’s in reach (they have an obnoxious heal), then go either clockwise or counter-clockwise pulling the others with whatever abilities you have. I recommend saving your Reckoning as you will need both your taunts at the ready- if you don’t have someone helpful CC’ing one of them, there will always be the one caster running out of range and thinking about blowing up the healer. The best way to handle them is to have the DPS focus fire and burn down the worst offenders as fast as possible- the Adepts and then Animators. If the rodeo lasts long enough you may get the chance to use your Captain America throw again; do this to pull in strays.
Turn the big ghosties on the last run to the Devourer away from the rest of the group as they have a frontal cone attack. This is NOT the time to chain-pull- they will buff each other if they are in range of each other, so suck up the Divine Plea cooldown and tank them individually.