Currently for Commanders, The First Sliver and Sliver Overlord give you card advantage, the latter and Sliver Queen are combo outlets, and Sliver Hivelord and Sliver Legion are there to increase staying power and damage
With only a few dozen games played, my early takes might be a bit off, but that's the thrill of new games, right
Lazav, the Multifarious Lazav, the Multifarious is a cheap Dimir shapeshifter that offers you some card selection, and together with good and cheap creatures, you can create an early powerhouse
I might be wrong ofcourse, but thats how it looks to me
The specific percentage chance of getting rare MTG cards in either the wildcard or seventh slot has yet to be announced
During your Main Phase: You can discard 1 card from your hand