Only an Assassin needs to deal combat damage to be able to cast for the two black mana freerunning cost, meaning Ezio can sit back on the battlefield to keep himself safe in combat while still taking advantage of his passive ability
It does take a few turns to set Serperior up through evolutions, but once it is, it can almost guarantee victory
Then theres Brotherhood Scribe, a creature that can tap to gain an energy, but you can only activate it if you have three or more artifacts, which wont be hard at all
Elena gets counters from all of your Historic casts as well, so she can get big fast and wear Equipment very nicely indeed
Mike wanted Gengar since he thought it would look great in the dark
Which was the other card to be banned from the Unlimited format as well as Modified, you ask