Weird, huh?

[Killer Joe]

Demonic Symbiosis
3BUW
Sorcery
Remove any one creature card from your hand. Play it as a creature enchantment card without paying it's mana cost and, it remains an enchantment. You control enchanted creature. Enchanted creature gains +X/+X where +X/+X represents the power and toughness of the creture removed from your hand. When the enchanted creature goes to the graveyard, return it to it's owner's hand and you gain life equal to it's original power and toughness.

 

[maraud234]

It is fairly cool idea. But I think it should be more like............

Sacrifice creature, add X 1/1 counters to another creature you control, where X is the sacrificed creature's mana cost.

or

Remove any one creature card from your hand. Play it as an enchantment card without paying it's mana cost and, it remains an enchantment.

 

[Killer Joe]

I like your idea about the counters, it's less messy.

Demonic Symbiosis
Sorcery
3WUB
From your hand, remove a creature card from the game. Put X +1/+1 counters on target creature where X equals the power of the removed creature. You gain control of the target creature. When the target creature leaves play, return it to owner's hand and they lose life equal to the creatures toughness and you gain life equal it's power.

"What's yours is mine and what's mine is mine."

 

[FoundationOfRancor]

Here, word it this way:

Demonic Symbiosis
3WUB
Enchant Creature
As an additional cost to play Demonic Symbiosis, remove creature card in your hand from the game.
When Demonic Symbiosis comes into play, put X +1/+1 counters on Enchanted Creature.
Gain control of Enchanted Creature
Whenever Enchanted Creature leaves play, return it to it's controllers hand. They lose life equal to the Enchanted Creatures toughness, and you gain life equal to its power.

 

[Killer Joe]

"...,where X equals the removed creature's converted mana cost."

 

[Captain Caveman]

Would this work?

Card Title: Demonic Symbiosis
Color: Gold
Type: Sorcery
Cost: 3WUB
Pow/Tgh: n/a
Card Text: As an addition cost to play Demonic Symbiosis
choose a creature card in your hand: Put that creature card
into play as a creature enchantment. That card now reads;
Enchanted creature gains +X+X. Where +X+X represents
the power and toughness of the creature card put into play.
When enchanted creature is put into the garveyard, you gain
life equal to that cards converted mana cost. Then return it to
your hand.


Man, it that card hard to word, or what?