Vaclaz in Normal mode is a combination of Pentaclypse, Anashti Sul and Field General Uktap.
You will see that Vaclaz has 4 adds that are with him. These adds control which version you get. If any of these adds die you will begin to trigger the Challenege Mode version of Vaclaz.
Vaclaz has three AOE's that are pretty potent so bring your noxious resistance. These AOE's also MUST be cured ASAP because if they begin to stack you will see your raid dropping very quickly.
Every 45 seconds or so one member of your raid will get a blue vision much like Field General Uktap if your guild every did that mob in Ykesha's Inner Stronghold. Whoever has the blue vision is the only person that can target a mob before he casts a raid wiping AOE. You have roughly 10 seconds to find this mob and hit it. All you need to do to prevent the wipe is to hit that mob and bring it back to the raid to be killed. The add can spawn anywhere around the outside of Vaclaz's platform. So be sure to stay as centered as you can as a raid to make the distance easier to travel.
Now, these adds do have a knockback as well so watch where you are standing that you do not get knocked off the platform.
The second thing to watch out for is a warning much like Twins or Anashti Sul in Palace of the Ancient One. You will get a message that You feel a powerful curse...
This is the time to stop doing wtv is you are doing and just sit there. This curse comes two at a time much like the other mobs. Only this time, if you cast you will not wipe raid initially but you will stun everyone next to you for about 10 seconds. That will likely spell doom for your raid because you need to be bunched up for this encounter.
Off tank the adds and be sure not to kill them. Handle the AOE's like champions and do not cast when you are cursed. Bring enough dps with you so the fight does not last too long. If the fight goes too long you risk killing the adds, or getting stacked up on detriments.
Disease Blast - High Damage Disease AOE (40 second timer, no swipe)
Poisonous Wave - High Damage Poison AOE (40 second timer, no swipe)
Toxic Torrent - Moderate Damage Poison AOE (40 second timer, no swipe)
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Crippling Nausea - Curse Effect - Triggers a AOE stun to those close to the cursed person (DO NOTHING UNTIL IT IS CURED!!)
http://www.youtube.com/watch?v=JRPet1pHTYk&feature=player_embedded