I promise you, a full uninterrupted Manifest Rage will spawn so many adds you're tanks will not survive. Even when we derp and spawn 3-4 adds we've had tank deaths. They hit hard, like really hard. The kiting of the Iron Star is not terribly difficult, the issue is your kiter probably has less than 10 total attempts of actually practicing the timing. I am my guilds kiter for Iron Star, and the fact that there were often 50 attempts between each good P4 attempt, it makes perfecting your strat difficult due to just not seeing the phase more than one or two times in a raid day. The Iron Star is buggy, stupid, has weird floor pathing issues, and sometimes doesn't "hit" Garrosh when you think it should. I am happy if I get 2 or less adds each time we kill this boss. There are spots where the Iron Star will juke you, take off in a weird direction for absolutly no reason. It just takes time and practice to learn how to find that sweet spot to keep the thing on you. I found an amazing weakaura from Brutal on Youtube, which has a really clean countdown from 10 to 0, and it helps a TON when predicting how fast you need to go.
Also remember, your kiter hitting the boss spot on is also reliant on your raid handling Malice. You may be kiting perfectly and watching his energy slowly tick upwards, but then your raid borks up Malice, and all of a sudden the boss just got a shit-ton extra energy, forcing the kiter to VERY quickly readjust his path. The Iron Star only moves so fast, so sometimes a bad enough Malice screwup is not fixeable by even the best kiter.
As far as Malice Immunities, we do it ever week with hunters, mages, and monks. I promise you it is doable. Just make sure you're raid is using the whole room to spread, and have someone (I do this very loudly and obnoxiously over mumble) calling out when the clump checks are over. The fact that you're seeing Phase 4 means a kill is not far off. Don't try and brute force it for a kill when you're this close. Phase 4 is a joke once you understand all the mechanics, getting there is the biggest part of the battle.
Sinthetik, Blood DK, BM Monk, GM, Exiled From Hell, US Premiere Daytime Progression Guild. 7/7 Mythic HM, 10/10 Mythic BRF. 12/13 Mythic, 13/13 Heroic HFC.
You don't want many of those adds. They hit way harder then 150k, and they hit nearly as hard as Garrosh himself. Getting 1-3 is certainly doable though. We have nearly done it with 9 up, but only because of insane avoidance streaks and the fact that they will vengeance cap your tanks fairly quickly, so his health melts.
If you let the whole channel go you will have several dozen adds, IIRC.
1) We leave our 2 SPriests (Dispersion), our rogue (CloS higher stacks), our mage (Ice Block), our monk tank (Zen Med) and a Disc Priest (close but not on the stack point) to heal/PW:Barrier them. I know Warlocks can do it as well on Malice 4, but it requires using all our CDs with a near perfect timing so we just use ours for Malice 2 instead.
2) The adds don't hit for only 150k, at least not on 25H. They hit for about half what Garrosh hits iirc. 1~3 adds are manageable with cds but spawning them all will most likely cause a wipe. I don't think any guild in the world has brute forced them so far. Also on a normal kill time in 25H you will go through 2 Iron Star phases at least, and your cds won't be up for the second one, so you'll have to learn to deal with an Iron Star at least once regardless, so why not just do it twice?
They do. Just checked my logs 3 weeks ago when our Iron Star kiter d/c'd and we got 31 adds spawning - they hits for 100-200k on tanks (Warrior and Monk). And most guilds nowadays killed Garrosh before 2nd Iron Star in P4.
Although I agree that trying to bruteforce through them is meaningless, I'd like to correct that technically, it *is* possible to bruteforce through it. On that wipe, our OT and 2 druids went YOLO-burn-him-down-while-we-kite-those-shit and we were able to burn Garrosh to 4-7% by the time we wiped. Was running a fairly normal 3 tanks 3 heals + 1 buyer setup, so theoretically, a better guild + more gear + running the 2 tanks 3 heals (which seem to be the norm nowadays for Garrosh) should be able to burn the boss before they wipe. Not seeing it happens in first kills, though.