This is where I will throw my general assassin ideas.
A good way to control shadow stepping being overused by non-'sins is linking shadow stepps to primary attribute.
All shadow step skills would have this attached onto them: "This skill takes 45...25...20 seconds to recharge. Then you link the recharge time of shadow steps to the primary attribute of sins. Either the entire line of shadow steps could be primary, or just the recharge. However, linking just the recharge time to primary only, while the rest is shadow, seems kind of odd.
When I first saw sin's, I thought there was a Dagger and an Off-hand Dagger. Since then, I always thought of the different possibilities that could have posed (both good and bad).
First off, you could have a Barbed Fighting Dagger and a Poisonous Off-Hand Dagger.
Assassin's could then extend conditions on both lead and off-hand attacks individually.
Also, after thinking about it, I decided that the Off-Hand Dagger could be a throwing dagger/item as well. Skills such as Crippling Dagger, Dancing Daggers, and Disrupting Dagger could be affected by mods on the Off-Hand Dagger. If the Off-Hand was a Icy Off-Hand Dagger, the attacks would be converted to Icy attacks. In fact, there could be an Off-Hand Mastery attribute line.
Attribute 1 (primary)
Critical attacks. This has several skills that trigger upon critical strike, change strength based upon # of critical strikes, or increase chance of crit strike.
Attribute 2 (dagger)
Dagger attack skills. The current Dagger Mastery is fine as is without the % chance of DS.
The attack skills consist of Lead, Dual, and a few Finish
Attribute 3 (Off-Hand)
The Off-Hand attribute line would affect how much damage you Off-Hand Dagger could do. There is also a % chance (based on the Off-Hand attrib level) that you sneak in a 2nd strike with your Off-Hand Dagger while normally attacking or using an attack skill (with the exception of off-hand attack skills, seeing as the off-hand dagger would be in use at that time.)
The attack skills consist of Off-Hand, Dual, and a few Finish
Defensive skills, as found in shadow arts.
In my opinion, chains should have more structure to them while being moldable.
Lead attacks would be attacks designed to spike a foe with a certain amount of health. In other words, lead attacks would be used to launch the first wave of assault on a foe. For the most part, these skills would be designed to harm specific health foes (such as the effect of Unsuspecting Strike). Some skills would function the other way, as a takedown to fleeing foes. However, the attacks wouldn't only offer bonus damage, they could also offer kd, interrupt, +dmg or +crit chance, and cripple. A lead attack has no "This skill must follow a ..." type of req., but some of the attacks may have bonus effects depending on whether they follow Off-Hands or not.
Off-Hand attacks are most of the Half-Ranged skills. For the most part, there are skills such as Scorpion Wire (a hex) that count as Off-Hand attacks upon trigger. Skills similar to Blinding Powder, Scorpion Wire, Augury of Death, Caltrops, Siphon Speed and gw:Dancing Daggers would be in this line. There would also be several skills with bonuses (+dmg, weaken stance, decrease AL/AL ignorance) that may trigger based off conditions, hexes, or lack of those on foes. Off-Hand Attacks are ideal for putting a small slowdown on foes off to the side (Such as using Siphon Speed or Caltrops on enemy warrior as he is rushing towards team monk) or for starting to drain foe of health a little before foe gets to you. An Off-Hand attack has no "This skill must follow a ..." type of req., but some of the attacks may have bonus effects depending on whether they follow Leads or not.
Dual attacks would almost (if not) always require a Dagger and Off-Hand Dagger to be equipt. They would have the req "Must follow a Lead or Off-Hand attack."(some duals may have specifics as to one or the other type). The main thing of dual attacks is ridding/disabling foe of extra defenses. Basically dual attacks may do something such as Remove Enchantments, Interrupt and/or Disable Spell, Cause Exhaustion, Cracked armor or Deep Wound or maybe even Reduce Adren (noting that a good warriors offense can be it's defense). They would generally do something that makes the foe more vulnerable to attack. While the foe is trying to undo the harm caused by your Dual Attack, you would follow with a finisher.
Finish attacks must follow a Dual attack. In general, these attacks are raw damage attacks meant to finish an already weakened foe. They basically consist of thing similar to Impale (- deep wound), Signet of Toxic Shock, and Signet of Shadows. They could have a few life steal attacks or ones that shadow step away from foe. Another possibility is having something like "Shadow Step to target alli. All adjacent foes that you have hit with a Dual attack take x damage." All in all, it is a finish off type attack.
The main thing chains needed was the ability to switch up the order of you attacks mid battle and actually have a tactical reason.
- Distracted Strike Lead. This attack does +x damage. If this attack follows an Off-Hand, this attack has +x% armor penetration.
- Powder Dagger(yea yea, lame name. Bear with it.) Off-Hand. If this does not follow a lead attack foe takes x damage and becomes poisoned for x seconds, otherwise target foe is blinded for x seconds. (By making the recharge on this attack somewhere around 8-10, you are forced to choose whether you want a blinded or poisoned and hurt foe.)