Hearthpwn

Trick (X) is a keyword that makes the first X attacks or spells have a 50% chance of effecting the wrong target. So if you play a minion with Trick (1), and then on your opponents turn they play fireball and target said creature, there is a 50% chance it will hit any other target, including heroes. The (X) will count down with every action until 0. 

Next keyword: Annihilate.

Sleep does not Silence permanently, effect will be gone when circumstances are met therefore it won't prevent a Deathrattle but It will prevent Knife Juggler's ability to the throw knife while he is under this effect.

Next Keyword: Void

Spore: Whenever the minion is moved from it's position (This may happen when another friendly minion is summoned or killed), do something. That can be either a positive or negative effect.

Next keyword: Dream

Dream X: Target minion returns to owner's hand at the end of X turns if it's still alive.

Next: Cursed

Curse: Deal (x) damage at the end of every turn to the owner of a cursed card.

Ex. 

Next keyword: Stagnation

Next: Timewarp

Cleanse means to remove all debuffs from a minion. This does not include damage they have taken.

Next: Promise

Edit: Got sniped! 

Submerge: Similar to stealth but causes the minion played this turn to be shown as a 0 mana 0/0. Your opponent will see that you played the card for 0 mana. This minion is also untargetable, and even if it is a class card it always will be shown as neutral. If an AoE is played, it will take the effect but will not be revealed unless it is at 0 health while submerged (it would then reveal itself and die). Once you attack with the minion, it loses Submerge. If it has taunt it is ignored (like a stealthed taunt).

The effect in all gives you the element of surprise depending on what the Submerged card's abilities are.

Here is what the card would look like:

A neutral example:

And some Class cards:

Next: Burst

Purge: When a minion with Purge deals combat damage to another minion, it Silences it (before death if it dies).

Next: Transmogrify

Betray: this card will go under your opponent's control in certain circumstances.

Next: Illusive