It works especially well with commanders like Narset, Enlightened Exile or Kykar, Wind's Fury since those run a large number of spells and naturally grow the board while interacting
Vilis, Broker of Blood allows you to spend one black mana and 2 life to draw a card by targeting itself, which you can repeat eight times until Vilis poetically succumbs to their own ambition
Once your tokens are gone, your spells get more expensive again, and you may have to rebuild from nothing
The fact that it does not have Flash was pointed out by many as a major downside, but I think that it is simply a necessary way to balance the card, as it would be too strong otherwise
Get 1 Rare or Mythic Rare, 3 Uncommons, 10 Commons, and 1 Snow Land (basic or tapped dual) in every pack
To force your opponent to discard an entire hand is akin to death, especially if that affects 3+ cards