1.) Will's Curse (the squid boss)
You'll have to fight four 'fake' bosses (~500K HP) before the real one will spawn (~700K HP). We usually just click the chalices from left to right to spawn the bosses -- the ordering doesn't seem to really matter.
The fake bosses are cake, and shouldn't be an issue. However, it might be beneficial to practice strategies on the fake ones before attempting the real boss; note that all of the bosses will randomly turn party members into either cups or skeletons. If a party member gets turned into a cup, you can free him by clicking on the cup. Alternatively, if a party member gets turned into a skeleton, you will need a M/P to purify the debuff. If the main tank is a skeleton for a prolonged time, it's pretty much a guaranteed wipe.
2.) Loyal Talomo
This boss has a permanent buff that decreases almost all physical and magical damage by a significant factor. There are some fire pits around the boss; if you click on one of them, you'll be given an interrogation needle. The needle lasts for 20 seconds in your inventory, and if you right-click it while you have the boss targeted, his permanent buff will be deactivated for a short amount of time. Do NOT click on all of the fire pits at once, only click on them one at a time as necessary.
DoTs remain unaffected, so stack those on as much as possible. It seems unlikely that it's possible to down the boss in the small timeframes the interrogation needles give you, so this fight usually lasts a long, long time. The boss has a cannon AOE which EVERYONE has to run away from, as it hits multiple times for 4k+ each. We ended up needing to kitetank it.
3.) Boulder Sidaar
Strategy: This boss is a pretty simple tank and spank. One thing to note, though, is that he reflects either physical or magical attacks, depending on which buff he has on. The physical attack reflection buff is an orange icon, while the magical attack reflection buff is a blue icon. You get hit for 1200 HP every time an attack gets reflected, so make sure the tank immediately stops attacking when the orange icon is up; as a result of this, aggro control is a legitimate concern.
4.) Lookout Luke
Strategy: This is probably the easiest boss of the five, if you have a good enough tank; it's another simple tank and spank, however there is a countdown-based attack (aptly named "xxxxx") which he can unleash on the tank for multiple hits. In our case, we had to keep the priest well informed of the countdown timer, so that the tank can survive all of the successive hits.
5.) Snow Blake
This is the hardest boss by far. She teleports you to her and then uses an AOE called "Queen Bomb" on you for 50K flat damage -- you can run away from the AOE, but in the latter half of the fight she will also cast an AOE root before she teleports you, which, if you don't get rid of, will result in immediate death.
We don't really have a clean strategy for this fight. Our strategy involves everyone other than two people staying dead... the biggest problem is the root; not every class can unroot themselves, so those who cannot are generally just left dead. Most noteably, the tank will have to be able to unroot himself, otherwise he'll be dead when the AOE hits. You might think that a priest will be able to cleanse the root off the tank, but there's a cooldown on cleanse which will result in the priest still being rooted and ultimately dead from the imminent Queen Bomb AOE.
However, it seems that self-damaging skills will break you out of the root. So in our case, we used an R/S with Blood Arrow constantly on (-200 HP per tick) to kitetank Snow Blake while the priest cleanses himself everytime he gets rooted and also constantly popping regens and heals on the kitetanker. It is a slow strategy, but it works, so we're not really complaining.
Yes, this means that other party members are left to fend for thsemselves (aka, left to die), and yes, this also means that Snow Blake is ultimately doable as a duo. This fight is one of the main reasons why I'm reluctant to upload the videos, as it's rather cheesy... we hope that we'll find a solution to the root and/or Queen Bomb AOE sometime soon.