Assassination [Rogue Ability se101]

Name: Infiltred attack
Casting Cost:4
rogue ability
Effect: it's not possible to defend until end of turn
Flavor Text: "They are ever here with us."

Name: Backstab
Casting Cost: 3
Effect: Target ally with cost 4 or less is killed.
Flavor Text: "He never saw it coming."

Name: Guerilla
Cost: 4 - Start in face down.
Effect: deal 1 dam to your enemy (ally/hero). this card goes back to the top of your deck when you finish the turn.
Flavor: "Stop me please!!"

Name: Fallen Serpico
Casting Cost: 3
Effect: Target opponent discard maximum two cards from hand at random.
Flavor Text: "Fall."

Name: Vile Strike
Cost: 4
Effect: Destroy target ally. You discard a card at random.
Flavor: What do you call a rogue that doesnt steal, cheat, lie or kill? A dead rogue.

Maybe adjust the cost. This let you kill a strong enemy like Aeon, but you have to sacrifice a card. Cost 3 maybe? I mean, hell, several classes can cripple an enemy for cost 2, this seems absolutely fair to me at cost 4, or maybe even 3 or 2.

Name: Backstab
Casting Cost: 3
Effect: Target Friendly ally attack cannot be defended. For the next 3 turns.
Flavor Text: "Rogues do it from behind!"

Name: Assassination
Casting Cost: 3
Effect: Destroy an enemy ally with cost of 4 or less
Flavor Text: "It will be quick, it will be quiet"

Name: Mission: Infiltration
Casting Cost: 0
Effect: Attach to an ally you played this turn. If attached ally damages the opposing hero, look at your opponent's hand and discard one card, then discard this card.
Flavor Text: "I've got a job that might interest you . . ."

I actually think that the "Mission" concept could be something that's used on numerous Rogue cards. "Mission: Assassination," "Mission: Surveillance," etc. The card comes into play as an attachment on the same turn an ally does, which is supposed to invoke the idea that the ally was sent on a specific mission. It's now up to the opponent to thwart that ally before he gets a chance to attack and do the deed. Seems like it could have a neat spy/counter-spy theme to it.

Cruel Strike
Cost: 2
Effect: Attach to weapon: Enemy allies damaged with this weapon lose 2 attack every turn.

N : Coup de grace (Coup de grâce if you want it more elitist) / Lethal strike
CC : 3
E : Next time targeted ally deals damage, Lethal strike goes to the graveyard and damaged opponent is killed after combat if an ally.
F : "All you need is a thin, long, and sharp dagger stabbed in the right place."

This card is not ongoing : many turns can pass before the ally deals damage, but when it does, Lethal strike kills the enemy and goes right to the graveyard. Even if opponent's ally is killed, he still defends and may kills back the lethal ally. The strike is lethal in the sens that the striken ally won't pass the night ;). Also, if target ally attacks or defends a Hero, Hero won't be affected. If unit or Hero was too armored for any damage to be dealt, Letha strike doesn't go to the graveyard.