New Assassin Build option: Umbra Witch

Assassins may choose the following Guild Training option, rather than the Bleak Disciple and Night Stalker options:

Umbra Witch
  By selecting this option, you lose the shadow step and shade form class features.
  Umbra Weapon Training: You gain training with the whip and the longspear. You also gain the Quick Draw feat as a bonus feat, even if you do not meet the prerequisites.
  Agile Combatant: You gain a +2 bonus to AC and Reflex against attacks made by enemies granting combat advantage to you, or affected by your assassin's shrouds. Also, you gain the umbran mobility and witch time powers.

You are a member of one of two clans that oversee history, an Umbra Witch. Awakened to the power of darkness, you have promised your soul to the denizens of Hell in order to win their trust and wield a power over time and space on Earth. Death will not be pleasant, when your time comes... but until then, you wield the power of darkness as a sword against your enemies.

Umbran Mobility Assassin Feature
For just a moment, time slows down, allowing you to turn a quick evasion into tactical movement.
At-Will ♦ Shadow
Free Action              Personal
Trigger: An enemy misses you with an attack against AC or Reflex.
Effect: You shift 1 square.

Witch Time Assassin Feature
Your mobility cuts through time itself; the world seems to slow to a crawl as you turn the tables on those who would dare attack you.
Encounter (Special) ♦ Shadow
Immediate Reaction              Personal
Trigger: An enemy misses you with an attack against AC or Reflex.
Effect: You shift your speed. You ignore difficult terrain during this shift, which you must end adjacent to the triggering enemy. That enemy then grants combat advantage to you until the end of your next turn. If the enemy is affected by 3 or fewer of your shrouds, you also add one shroud to it.
Special: You regain the use of this power the first time you are bloodied in an encounter.

Yenal's Favor Assassin Utility 6
With a sly smile, you do no more than fix your knowing gaze on your target, filling it with dread of what's to come and bolstering your confidence at the same time.
Daily ♦ Shadow
Minor Action              Close burst 3
Target: One enemy in burst subject to at least 1 of your shrouds.
Effect: The target grants combat advantage to you until the end of your next turn, and you gain temporary hit points equal to your Constitution modifier plus your Charisma modifier.

Gaze of Despair Assassin Utility 10
You strike a provocative pose and beckon your enemy to attack you. It's risky, but the tauting distracts it from realizing you've set it up for a quick and brutal reprisal.
Encounter ♦ Shadow
Minor Action              Close burst 2
Target: One enemy in burst subject to 2 or fewer of your shrouds.
Effect: You use your assassin's shroud on the target, which is subject to two shrouds rather than one. You grant combat advantage to the target until the end of your next turn, and if the target successfully hits you with a damaging attack while you grant combat advantage in this way, it deals an additional 5 damage with that attack.
Akko's Reprisal Assassin Attack 3
Drawing on shadowy magic, you compress the power of your opponent's missed attack into a sphere of force, then detonate it while you make a hasty exit.
Encounter ♦ Shadow, Implement, Force, Necrotic
Immediate Reaction              Close burst 1
Trigger: An enemy misses you with an attack against AC or Reflex.
Target: Each enemy in burst
Attack: Dexterity vs. Reflex
Hit: 2d8 + Dexterity modifier force and necrotic damage. If the target is subject to at least one of your shrouds, it takes additional force and necrotic damage equal to your Charisma modifier.
Effect: You shift two squares.

Tetsuzanko Assassin Attack 5
Drawing on demonic might, you ram your shoulder into an enemy and send it flying across the battlefield.
Encounter ♦ Shadow, Weapon
Standard Action              Melee weapon
Target: One creature
Attack: Dexterity vs. AC
Hit: 2[W] + Dexterity modifier damage, and you push the target 5 squares.
Yaksi's Grace Assassin Attack 9
With incredible speed, you interpose a shadowy barrier in front of an enemy's attack, then deliver swift punishment and escape before the enemy even realizes what's happened.
Daily ♦ Shadow, Weapon
Immediate Interrupt              Melee 1
Trigger: An enemy in range attacks you with a melee or close attack.
Effect: You gain a bonus to all defenses against the triggering attack equal to your Dexterity modifier. If the attack misses, make the following secondary attack against the triggering enemy:
Secondary attack: Dexterity vs. AC. If the target is subject to at least one of your shrouds, you gain combat advantage for this attack.
Hit: 2[W] + Dexterity modifier damage, and you shift 2 squares.