Guide
Turn 2 is where the difficulty steps up quite a bit. It requires all 8 party members to be playing their best game and one slip up will cause a wipe. There is some leniency on the way to the main boss however you should try to avoid mistakes as the main boss will not be so forgiving. Although the time limit for this turn is 90 minutes you are on a 12 minute timer as soon as you engage the first boss, and once this time runs out you will wipe. Below is a detailed guide for turn 2.
Turn 2 sees a return of ADS, the first boss from turn 1. Only this time he is stronger and has more attacks. The turn has no trash monsters, only 7 mini bosses and ADS. You do not have to kill all 7 mini bosses but there is a minimum of 3 and most groups will only kill 3 of them. The way the turn works is that each mini boss (node) you kill will remove an attack from ADS; this being the attack that the mini boss has. So to begin with ADS has all 7 attacks. On the downside, it will also add a negative effect on the boss. Some you should avoid.
So the general idea is that you should get to ADS via the best possible route. There are two that work well and they both avoid Sector VII on the map. Do not kill this node. While it removes the annoying Allagan Rot from ADS (more on this later) it will give him a haste that makes the fight next to impossible. Allagan Rot is easy to deal with so it’s not worth going down this path.
Preparations
You should use the standard party setup of 2 tanks, 2 healers and 4 DPS for this turn. Ideally one DPS should be a Bard because like with turn 1 you will need a silence rotation for High Voltage. The mechanic is the same and all nodes as well as ADS will use it. Missing this silence can cause a wipe due to the paralyze. You need at least two people on this because the nodes will use High Voltage again before the BRD can use Blunt Arrow again. PLDs can be part of the rotation with Spirits Within.
A tank rotation system is necessary throughout this turn because each node and ADS will add a stack to whoever is tanking, and this increases the damage they take. When the tank is ar around 5 stacks they should stop tanking and give control to the other tank. This is a repeating process for the remainder of the turn.
Give 5 of your players (not tanks) a number marking 1-5, this is important for the Allagan Rot rotation later on.
Making your way to ADS should not be challenging, the nodes along the way are fairly easy to kill providing you follow the above preparations correctly.
ADS
ADS has a lot more HP than the nodes, as you would expect. He comes with the same High Voltage and laser attacks as ADS from turn 1. You should know how to avoid these by now. He will also have some new attacks dependant on which nodes you did and did not kill. Most of them are quite simple; in fact Allagan Rot is the only one you should worry too much about.
The way Allagan Rot works is that around 75% HP he will cast it on a random party member. This gives that player a 15 second countdown and once it hits 0 it will explode and wipe the entire party. You cannot survive that, so how to get rid of it? Simply touch another player and pass it on to them. Who you give it to should be based on the numbering you set up earlier.
Upon passing it you will gain a 45 second resistance to it so you can not get it back until then. What this means is that you should not be passing it too fast. You should wait until around 5 seconds left on the countdown and then pass it on. Repeat this until the end of the fight, or if everyone stacks together after the first round of passing then the resistances should make it so that the correct player receives Allagan Rot at the right time anyway. This is easier for Allagan Rot but makes the laser attack from ADS more risky.
This is pretty much the whole fight, if you get Allagan Rot correct, avoid the lasers and avoid High Voltage then you are on your way to winning.