So, since we are getting more 50s on both sides I wanted to post some helpful hints on the bosses for IT.
The first Boss Brood Mother Veroxa (think that is spelled right)
when you enter her chamber she will start the fight. The tank will tank her where she stands. All ranged dps will be by the corner closest to the boss at first. During the fight you will have random baby spiders spawning and attacking these need to be burned down because it will effect the healers cast time.
75% 50% 25% she will emote this is when the range need to get out of sight or get hit with a pretty bad poison. She will also run to a cocoon that is positioned on each corner of the room and open it up to create a defender spider. These spiders have to be burned down because they hit pretty hard. To get the achievement don't kill the defenders.
That is Veroxa in a nutshell.
Caor Ashtone is almost the same as he was in the original IT.
He still does the MS type of debuff on the tank that needs to be decursed ASAP. He will also do a stacking debuff on the entire party that makes him do more damage throughout the fight. He also does a pbaoe around him that does mediocre damage at first and rises with the damage debuff stacking.
So basically Caor is a Tank and Spank.
The three kings.
The three kings are basically the same but they have buffs.
Each time one of the kings die they will put a debuff on the party. However, this can be avoided with a 6 pt necromancer ability called Consumption. You have to eat the buff twice.
This will stop the Debuff.
Some tanks have issues on the 3 spawn trying to get aggro on the cleric and the mage. It depends on the tanks spec. Remember all melee behind Humbert because his cleave is beast.
The bone lord.
During the bone lord fight is a tank and spank. He will emote throughout the fight. the range will line of sight the emotes outside of the room on the sides of the arch. The melee run around the pillar since the bone lord doesn't move. You have to LoS this. He will spawn skeletons on when he demands your bones these skeletons do roughly 2k per hit (on cloth). The second emote he makes your blood boil. This one is a 10 second fear that does 1k per second. This is a curse it can be decursed.
He will randomly go immune for 10 seconds this can be consumed.
Ragnoth the Despoiler.
He does a 360 degree melee aoe swipe.
He also puts up a buff that does aoe damage to melee too. This can be consumed.
Eliam also spawns in this fight to protect you from ragnoth's fire.
During the Eliam spawn he will snare people that are running to the circle. Wild abandonment from chloromancers can cleanse this.
Totek the Ancient.
This is a knock around tank and spank.
The tank keeps Totek away from the ranged at almost max spell range (25m) he will knock the tank around when he throws his fit doing some heavy damage.
During his fit he will knock loose boulders from the ceiling that hits the ranged that do around 4k damage and stuns the person. These can be avoided.
If you are a melee warrior Way of the Mountain makes you immune to Totek's fit.
(The reason I say fit is because he sits there and smashes the ground like a three-year-old who cant have a cookie).
That is Iron Tombs Expert in a nutshell I hope this helps you guys