This is a comprehensive guide to new players who want to play support in the 3 necros 1 Barb Rathma's meta, but don't know how to play. There are lots of gearing and skill spec guides, but most of these guides I noticed don't actually tell you what to do or why.
You are the leader of the pack. Nothing gets done without you, you play the most important role in the meta. Without you, Rathma's dont get essence, and the Barb can't deal damage anyways. That being said, you need to skip from elite to elite, and do your best to skip all of the trash. You set the pace for the runs, and determine the speed.
Your globes spawn mostly BEHIND you (mostly). That means you always need to be ahead of the party, so the barb and other necros can pick up the globes. If you stay still, everyone dies.
VERY IMPORTANT: you can ONLY cast one spell (with a casting animation) at a time! That means whenever you are devouring, you cannot cast death nova or corpse lance until the animation is finished. The same is true in reverse, you cannot devour, if you are casting corpse lance or death nova. While getting zodiac procs is very very important, globe generation is your number 1 priority. That means you need to determine where, and when, and in what situations, you can afford to proc your zodiac. Each second you are proccing your zodiac, you are not generating globes. Be careful!
It is VERY IMPORTANT also that you MANUALLY cast corpse lance. Waiting for corpse lance to apply its debuff to a specific target takes far too long, as its only one lance per corpse consumed. If you have been gearing your gear correctly, you can apply up to Seven (maximum IAS) lances with one click. You probably won't get the gear to get seven lances, but having IAS on most of your gear will allow you to get a decent number. 1.65 attacks per second means you have around 3 lances per click, while 1.75 attacks per second means you have 5 lances per click. One click adds a 25% chance to crit to a mob, while two ups it to 50% (10 corpse lances). Manually click on all blue and yellow mobs at least twice to get that buff up!
In a short run down of play style, you will always be staying ahead of the pack, one to two screens ahead, clicking corpse lance on any blue or yellow mob, and when the party arrives, generating globes for the barb to hoover up. Once the elite has died (watch your console), immediately zip away and find the next pack
For the Support Barbs:
It's incredibly important to stay on the same screen as the necros. Picking up globes has a range bonus, and if the necro is too far away, it won't get the benefit of the pick up.
Your second priority is to Rend and Shout all elite mobs. Rend – Mutilate applies a 10% damage debuff, and Shout applies a 25% debuff. combined with the necro's lances, this should allow the rathma's to one shot any elite mob.
you need to keep the dps in pace with the znecro. In between mobs, constantly cast sprint while running with them, and keep them alive with IP
Break down of play style: Keep the IP up on all necros 100% of the time, find the elites first, Rend and Shout the elites, zoom around picking up globes, and then cast sprint on the dps to zoom the dps to the next mob
Anyways, hope this helps you out! happy ratting!