If this is the second time this ability has resolved this turn, draw a card instead
Firstly, it sends unplayed exiled cards to the yard, which will undoubtedly include some lands
BPhillipYork: This is really too expensive unless you have some trick to manipulate the top of your library
Its not unreasonable to think you might just draw twenty cards, right there, and if your deck contains a very unusual amount of mana, you might not be far from drawing your whole deck (especially if youve got a couple of Dakmor Salvages somewhere in the mix, making it completely deterministic that you mill your deck, fill the battlefield, and set up some graveyard kill)
This version of the deck doesn't rely on spreading damage as much as the other versions because it's so good at stacking damage quickly and removing threats from the board as soon as they're played
If I wanted to do this, Id start with a vanilla that could end the game via commander damage, so 3-Hit Club members like Yargle, Glutton of Urborg, Terrian, World Tyrant, or Kalakscion, Hunger Tyrant