Watcher Sliver

This creature can't be blocked except by artifact creatures and/or red creatures.

You can't cast Serra Avenger during your first, second, or third turns of the game. Flying, vigilance

2: This creature gains flying until end of turn. 2, Sacrifice this creature: Draw a card.

Protection from black; flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.) Suspend 3—1WW When the last time counter is removed from this card while it's exiled, create a 2/2 black Knight creature token with flanking, protection from white, and haste.

All Sliver creatures get +1/+1.

1, T: Untap another target artifact. 3, T: Target creature can't be blocked this turn.

Flying As long as this creature is untapped, it gets +0/+2.

Create a 4/4 red Giant creature token. At the beginning of your next upkeep, pay 4R. If you don't, you lose the game.