Flying.Whenever Hakka, Whispering Raven deals combat damage to a player, return it to its owners hand, then scry 2
There are so many fun things to mess around with when building a mill deck, no matter what format youre in, that picking something dull but efficient almost feels like a copout
#5 clearly the answer is to break singleton ok sorry more seriously a difficulty is making sure the intersection of black's weaknesses (unable to deal with artifacts, enchantments, and perhaps certain green creatures), still leads to interesting games for both players when those issues come into play
In particular, Astellar of the White Forest is a real standout, with the cards value reflective of its potential potency
Previously, Rakdos decks relied on options like The Cruelty of Gix, Coiling Rebirth, or Push // Pull, which could be cast on turn five or six