The deck is incredibly strong and, thanks to Murderous Rider, Dark Salvation and Languish, has fairly good removal as well
A card such as Spell Pierce you play when you need specific solutions however Force Spike is playable much more generally as a way to improve your early game and tempo capabilities
First, take two cubes and link them together
Vren, the Relentless bends the archetype toward control: it exiles your opponents dying creatures and then hands you a pile of scaling rat tokens at each end step for doing it
I don't like the inconsistency of relying on big ramp and I don't think the payoff is worth it with these kinds of cards
First, the ones that can change their own creature type: As I said in my tribal article, this mechanic (designed by Mike Elliott) plays into a common blue theme, the ability to change things