Thaddius can be very difficult for people who have trouble distinguishing between right and left and/or using their eyeballs. To start the fight the raid has to kill two mini bosses, Stalagg and Fuegen. You need to split your dps and your healers between the two platforms so that you kill both of them within a few seconds of each other. At 60, if you didn’t kill them at the same time, the one still alive would enrage and kill a whole bunch of people. I am not sure if that is true anymore, but my raids always kill them at the same time because we don’t want to test it and it is pretty easy to coordinate dps to get them both down at the same time. The mini bosses have a beam of lightning attaching them to a thingy on the ceiling and if they get too far away, the tether will break and they will enrage and kill a bunch of people. At 80, there is no reason for them to ever move far enough away to break the tether. Stalagg and Feugen periodically throw the tanks from one platform to the other at the same time. They share threat so when the Stalagg tank gets thrown to the Feugen platform, he will automatically have aggro on Feugen. At 60, positioning was very important and if the tanks wasn’t standing in the dead center of the platform, when the tank throw happened, he would bounce off the ceiling and land in the slime below and then the mini-boss would run down to the tank, off the platform, breaking the tether and enraging and would then kill a bunch of people. At 80, you don’t have to worry about that, you can no longer bounce off the ceiling or anything and thereby ‘miss’ the tank throw. The mini-bosses don’t have any special abilities, but they do hit the tanks kinda hard so the healers need to be paying attention.
Once you kill the mini bosses, the next challenge is jumping. You have to jump off of the platforms of the mini bossess, down to the platform where Thaddius lives. If you jump to early, you will miss and end up in the slime and everyone will laugh at you. If run off the edge without jumping at all you will miss and end up in the slime and everyone will laugh at you. If you miss the jump, you have to run back to the entrance to the room and then back up to the mini boss platforms and then try the jump again. You have around 15 seconds from when the second mini boss dies to when Thaddius becomes active so you can take a little time and be sure that you get it right. I like to move my guy off to the side and that neither my character nor the point on the platform I am going to jump from are covered up by the corpse of the mini boss. As stupid as it sounds, I think most people miss the jump because they try to jump right away – when everyone else jumps – and they end up looking at the wrong character and mistime the jump. I just take my time and move off to the side and make sure I know exactly where my guy is. If you do miss, another tank should be able to pick it up just fine and you can taunt him back later or you can just dps.
The major mechanic of the boss is polarity shifts – just like the guy from Heroic Mechanar. If you stand with people of a similar charge, your damage is multiplied and if you stand with people of the opposite charge, you do a bunch of damage to each other and someone probably dies. There are plenty of strategies for how to shift around and deal with the polarity changes and I’ll share what my guild does which may or may not work for you. We tank him right where he stands when the encounter starts and everyone starts off right on top of the tank. When the first polarity shifts happens, everyone who has a negative charge moves to the left and everyone with a positive charge moves to the right so that the three points formed by the negative camp, the boss and the positive camp are all in a straight line (Neg—-Boss—-Pos). Everyone, ranged and healers included, stands at max melee range and the hunters stand as close as possible while still being able to shoot. It is important that melee and the tank are at max melee range so that they don’t cross charges with melee on the other side – the hitbot is pretty big so you can be off by a little bit and be ok. It is important that all the range are as close as possible to the melee to ensure that you are stacking all of the charges. Since the damage increase from the charges is multiplicative and not additive, it is very important to get all of the charges together, especially in the 25man where the enrage timer can be tight (the enrage time in the 10man is MUCH more forgiving).
The boss periodically casts a polarity shift that will change the polarity of some of the people in the raid while others stay the same. After the polarity shift, you have about 5 seconds before the charge goes active and you start damaging opposite charge people or multiplying same charge people. The other reason for having everyone as close as possible to the boss without crossing charges is so that you can quickly get to the other side if your charge shifts. The way my guild handles the shifts is to have everyone whose charge shifts run in a tight arc around the left side of the boss to get to the other camp while people who didn’t have their charge shift just stay put. So if you are a negative and you get changed to a positive, then you run around the boss to YOUR left, which will be towards the back of the room and if you are positive and you shifted to negative, YOUR left will take you around the boss towards the front of the room. We could just tell everyone to move clockwise around the boss when their charges shift and have the same effect, but some people are just dumb and I guess understanding ‘run to YOUR left’ is easier than ‘run clockwise’.
Once you get everyone shifting and stacking up properly, its just a tank and spank fight. He does a chain lightning thing that will hit a few people but its easily healable and he doesn’t hit the tank particularly hard. Between the jump and the shifts, the fight is basically one big idiot check – if your raid can jump and remember left and right, you will win.
But some peope will inevitably screw it up and get themselves killed, especially if they are new to the fight. You can battle rez people, but when they get rezzed, they won’t have a charge so when they pop up in the middle of 5 or 10 people with a charge, they will be killed instantly. If you are going to battle rez someone, have the druid run off to the side, away from both groups and cast the rez from there and have the person getting rezzed wait until the boss starts casting a polarity shift before accepting the rez. That way, they will get a charge when they pop up and will have a few seconds to run to the appropriate side. The same idea goes for people who miss the jump. You will probably be out of range for the first polarity cast while you run back to try the jump again, so, when you land on the boss’ platform, stand away from both groups until you get a charge.
In the 25man, if you have more than 3 or 4 people die, you will have a very hard time beating the enrage. In the 10man, if you lose a few people early, you can still beat the enrage if the remaining dpsers aren’t terrible.