Magic: the Gathering cards

[SDragon]

I was going through some old text files of mine, and I happened to stumble across a file that had a couple of Magic cards I designed. The first two were designed specifically for this site, and were originally posted in their own thread. These were based on the Halloween ranking system we had at the time (back in '06, it seems), as the skulls reminded me of the black mana symbol.

(b)(b)(b)
Creature

Swampwalk

(b)T: CBG Will o' the Wisp deals 2 damage to target creature. If target creature is not in a graveyard at end of turn, you gain control of it. If target creature is in a graveyard at end of turn, place a +1/+1 counter on CBG Will o' the Wisp.

Place a +1/+1 counter on CBG Will o' the Wisp each time it deals combat damage to a creature.

2/2

"Ouch. Where is Goog?"
-Goog, goblin wanderer

(mana cost TBD)
Enchantment

(u)(2): A copy of Harbinger of Denial is put under each player's control. Copies of Harbinger of Denial do not have this ability. Any player may activate this ability as if it was a sorcery. This ability can only be activated once per turn.

(u)(u)(1)T: Counter target spell.

At the end of your turn, all copies of Harbinger of Denial under your control are removed from the game.

"Authority must be shared."
-Inscription on the Harbinger Stone.[/quote]

So what do you guys think? Is there a way to make this concept a little more viable? Can I make one for all five colors?

For that matter, would any of these cards be worth playing? Do you think dynamics like these would make the game more fun, or more frustrating? Input, of course, is always welcome!