For those that don't want to read the full analysis, here is the short version:
When using an assassin in a full AI party, overkill makes some of the skill sequences less effective than they could be, especially with Death blossom + Moebius strike combo.
Ending build became:
[skill]golden fox strike[/skill][skill]wild strike[/skill][skill]death blossom[/skill][skill]moebius strike[/skill][skill]critical eye[/skill][skill]critical agility[/skill][skill]assassin's remedy[/skill]
The last skill slot is optional, usually taken by Pain inverter.
Build core: Unblockable initial strikes coupled with assassin's remedy almost guarantee successful Death blossom-Moebius combo initiation and low recharge of 4 seconds on both also enables fast target switching. Critical eye and Critical agility provide energy management, while assassin's remedy acts as a backup enchant and blind counter.
For those interested in more deep views, I made the following observations:
The heroes and henchmen (AIs) always attack the same target as the player. Given that assassins are designed to kill a target very quickly, on their own this may work against some assassin strategies. Overkill can significantly lower the actual effect of the assassin. In PvE, the assasin usually faces either many easily killed targets or a single very hard to kill target (a boss, for example). With the easily killed targets, it becomes important to be able to switch targets quickly (so skill recharge must be considered), while the bosses are usually tough enough that a standard "spike" that would kill instantly is not enough to finish off the boss.
SECTION 1 - THE BLOOMIN' COMBO
Once the combo is started up, there is no doubt that this is a seriously deadly long term source of damage. However, the sequence must first be started up, making the ability to reinitiate the sequenceafter the first enemy is killed very important. Also, the sequence is often overkill.
SECTION 2 - GETTING THE COMBO STARTED
My current preferred version startup sequence was [skill]golden fox strike[/skill][skill]wild strike[/skill]. This sequence has the advantage of only 4 second recharge with the added advantage of ignoring blocking. Also, on its own, it makes for two high damage attacks - useful when you find yourself targetting an already damaged foe, which may well be taken out by these two alone. Note that the golden fox strike delivers its damage unconditionally - even if your enchantments are stripped.
The shortest way to start the sequence (that I found) was being enchanted (preferably with Critical agility) and then using [skill]golden phoenix strike[/skill]. Probably the shortest way to start the combo, it starts the AoE damage coming in as the second attack. In theory, Moebius strike should recharge the golden phoenix strike by the time you need to switch to a new target, however, it must hit an enemy under 50% health. If you are alone, no problem. With AI's attacking your target, this is not very often possible to pull off - the enemy will be killed too quickly. Also, after the first target, the other targets will be already damaged by the AoE of your own attacks and the group elementalists. I actually found I spent half the time waiting for the remainder of the 8 second recharge to pass, effectively halving my actual damage except with really tough targets, like the destroyers.
The "falling" skills [skill]falling spider[/skill] and [skill]falling lotus strike[/skill] suffer from the same long recharge problem, and the knockdown condition is rather harder to acieve than the simple "enchanted". The other skills don't break the standard three stage lead-off hand-dual sequence.
A nice example of "all AIs focus on my target" problem would be [skill]unsuspecting strike[/skill], as all ranged attackers in the party will target your own target, usually taking its health down below 90% before you even reach the target, losing you the conditional damage bonus.
[skill]black mantis thrust[/skill] offers a conditional cripple, however, in PvE, kiting doesn't happen. Enemy happily charges in
[skill]jagged strike[/skill] My previous sequence starter, this little baby delivers a long case of bleeding. Now, the total of damage the bleeding causes is significant (about 90 damage in 15 seconds), however - with an assassin in play, enemies die in less than 5 seconds (you will notice that the 4 second recharge of the proposed sequence is still a slight limit
) and that quite a few foes are immune to bleeding. A potential second choice.[skill]Dancing daggers[/skill] are a potential, unfortunately, they require investment in Deadly arts - a field the assassin in PvE usually avoids.
[skill]sneak attack[/skill] is a potentially nice one. While it offers no damage, it keeps the enemy nicely blind, lowering damage to you. Switch to it if you know you will be facing a dangerous attack using opponent, otherwise go for a damage skill.
Other lead attacks have long recharges, making them unsuitable to PvE.
SECTION 3 - the chain is only as strong as the weakest link
There are only two off-hand attacks that have a low enough recharge to be considered. Wild strike and Golden fang strike. Both are nice choices.
[skill]wild strike[/skill] works very well with Golden fox strike, as it will work through a defensive stance and also end it, taking care of many forms of blocking, making way for the main sequence to grind away. Also offers nice damage that doesn't go away.
[skill]golden fang strike[/skill] simply causes a deep wound. This is better damage wise, however, it loses on utility, unblockability, and is useless of someone else is inflicting deep wound (like Talon).
SECTION 4 - The other half of the skill bar
First, a very nice skill is [skill]Critical agility[/skill]. This PvE skill may be nice for the IAS boost, however, the assassin should also appreciate the long lasting armor boost (making the assassin less of a squishy) and the fact that this is an enchantment that lasts all combat, which is important for the very useful "golden" skills.
The IAS boost doesn't really matter all that much damage wise (just makes the combo faster), but it is important for [skill]critical eye[/skill]. These two together are quite adequate energy management for the build.
I only recently discovered [skill]assassin's remedy[/skill] which is actually a very nice way to deal with conditions, granting the assassin the ability to remove many conditions, most importantly blind. Also, it is a cheap enchantment (5e) that can be kept up all the time (30 seconds, only 20 recharge - full coverage) to enable the "golden" conditional effects.
Lastly, some PvE only skills might be mentioned.
[skill]finish him[/skill] very powerful, but then - if you have the enemy on the ropes enough to use this, he'll fall to another death blossom combo, too... Still, sometimes, this is like a "Please die now so I can move on to the next enemy" skill.
[skill]you move like a dwarf[/skill] very useful. Works as ideal instant interrupt that works even through another skill, is a snare that slows the enemy down, even does some damage.
[skill]pain inverter[/skill] one of the mightiest skills ever, it can always come in useful, even if just as a short lasting empathy on a melee attacker (worst use). Ideally, of course, you'll slap it onto an enemy elementalist.
These are my observations. I would welcome any thoughts on the topic of an assassin working with a full AI party.
