Throwing Knife [Rogue Ability se103]

[Hednez]

Name: Hidden Knife
Casting Cost: 2
Effect: 3: Target ally receives 1 damage. If the ally was destroyed through Hidden Knife, draw a card.
Flavor Text: "Excuse me, but you've got a knife stuck in your back!"

A simple ally-finisher to draw a card. That's the whole idea about Hidden Knife; minor damage, but getting an extra card for killing.
So just to be clear: You attack someone and the attacked ally only has 1 HP left now. You cast the effect of Hidden Knife and draw a card. Also nice 1/1 killer (Sparks)!
I think its costs are fair, but if you want to lower them, do your magic!

[onionknight]

Name: Throw Weapon
Casting Cost: 3
Effect: 1 resource - Your hero gains +1 attack and his/her attack cannot be defended until end of turn. Destroy any weapon used to attack with.
Flavor Text: "I have no use for this anymore. You can have it."

[Right_Shift]

Name: Preparation
Cost: 5
Effect: Ongoing: Whenever target hero is attacked, they deal 1 damage to their attacker before taking damage. This attack is separate from defending.

[SoulShocker]

Name: Throwing Knives
Type: Rogue Item
Casting Cost: 3
Effect: (2): Deal 1 damage to any target.
Flavor Text: Never bring a sword to a knife fight.

[MikuHatsune]

Name: Throwing knife
Type: Rogue ability
Cost: 2
Effect: Destroy Rogue weapon used by hero and damage target equal to weapon attack
Flavor text:" Plan B"

[Mr Grimm]

Name: Quickdraw
Cost: 2
Effect: Target ally gainst +1 attack. Target ally can not be defended against until beginning of next turn.
Flavour: There are the quick, and then there are the dead.

[Ness]

Name: Flying Dagger
Casting Cost: 2
Effect: Play face down. The next enemy ally to be summoned takes 2 damage.
Flavor Text: "A surprise attack from the shadows."

[Hednez]

Name: Flying Dagger
Casting Cost: 2
Effect: Play face down. The next enemy ally to be summoned takes 2 damage.
Flavor Text: "A surprise attack from the shadows."

Sounds like the idea that Fry has already posted, only that your costs are 1 resource more expensive:

Readied Blade
Cost 1
Rogue Ability - Tactic
Play this card face down. The next ally your opponent plays takes 2 damage.

[Kaylie]

Name: Unfair fight
Type: Ongoing Ability
Cost: 2
Effect: Play faced down. Next friendly ally targeted by an attack from an opponent's ally gains intuition, allowing retaliations before being struck by an oncoming attack.
Text: Hey no throwing knives (cameo to the countless throwing knife names out there before me )

[Chaosnake]

Throwing Knife
1
target ally takes 2 damage
"Hey man, nice shot!"