magic 2012 booster box the Gathering M12 Core Set Fat Pack : Toys & Games and one rules insert MTG 2012 Core Set Booster

What are the weaknesses and retreat cost of this Ekans card

It was also the first time they'd been taught by someone who looked like them

Honestly, its kind of hard to wrap my head around how strong this one is

By the way, Magic Online Commander fans, it looks like Ill have two rare Tuesday nights off December 4th and December 11th, so I thought Id dedicate those free nights to playing some Commander on Magic Online, and Id love to play with some of you, so add me to your buddy list (Im blairwitchgreen) and look for me online around 8 PM Eastern time and lets have some fun

Personally I use this kind of limitation on the cards that are easier to use on each deck, to make them more fair

C Common Prometheus, King of the Shadows X DARK Level 4 [ FiendEffect ] ATK 1200 DEF 800 If this card is Normal Summoned: Banish 1 or more DARK monsters from your GY, and if you do, this card gains 400 ATK for each, until the end of this turn