When she enters, you look at the top ten cards of your library, and for each card type put up to one card of that type into your hand (the rest of the cards being tucked to the bottom of your library)
MacCready, Lamplight Mayor gives skulk to your small creatures, making them unblockable by bigger creatures and helping your attacks with tokens get through blockers, especially if you dont have any anthem or +1/+1 counter effects out on the field
Grim Servant Tutor on a creature, based on devotion to black
The lone blemish that the mechanic has is the existence of Alrund's Epiphany, and while that card maybe shouldnt have foretell printed on it, its intrinsically powerful enough that the mechanic isnt entirely to blame
Phyrexian Arena Pain for pleasure Phyrexian Arena is a Commander staple because this three-mana enchantment is black and lets you draw a card at the beginning of your upkeep for the cost of one life