Very interesting. More cards like this need to come out; more powerful than they should be for their cost, but have a negative side. Just like what I'm doing for my Mage series.
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OK thematically; I think this should be a specific element. I understand the thinking behind Other I think, but it doesn't feel right for what it is. Perhaps water. And just go into Photoshop and adjust the levels to make the reds become blue. But its whatever.
Secondly, I'm not trying to like tromp on your idea, but hear me out; as far as the name, I'm not crazy about Blood Striker/Assassin. That sounds like a humanoid creature like a black ninja with red highlights. But when I look at this creature, I think of something more like a leech. Maybe Leech Striker? Feels a bit more appropriate for what it looks like. I really like the image though! Did you use some sort of reference or was it just purely your imagination? Looks very cool, but I really feel that you could develop it further. More detail/shading, and you'd have an ace picture.
