Quote from TildeI'll give it a go.
EDIT FOR ENTRY:
My restriction: A card's rules text can't use the Xth letter of the alphabet, where X is that card's converted mana cost. For example, my card has CMC 4, so I can't use the letter D anywhere in the rules text.
Creature - Spirit (u)
Other attacking and blocking creatures you control have Hexproof.
Didn't you break your own restriction?
I guess I'll try this out.
Restriction: The design can't incorporate odd numbers in its converted mana cost, power and toughness, or number of colors (meaning that it must have 0, 2, or 4 colors).
Creature- Phoenix (R)
When Flameborn Sire dies, put a 0/4 white egg creature token with defender onto the battlefield. When that creature leaves the battlefield, you may pay . If you do, return a phoenix card from your graveyard to the battlefield.