Then you can give everything from your graveyard haste, to swing faster, as well as from exile casts to Command Zone ones
A blasphemous thought to many of you reading, Im sure
Your spells cast from your hand have cascade so long as they have a mana value equal to the amount of life lost by your opponents this turn, which might take some set up but can be very strong
At just 1GW, Arahbo, Roar of the Worlds ability to give an attacking +X/+X, where X is its power, can quickly make your creatures a game-ending threat that are hard to stop without removal thanks to that lucky cat also getting trample
Myra's activated ability targets only the instant or sorcery card in your graveyard
Getting eight cards is huge, and often youll get something back, which is the usual downside of spending a card just to mill someone