I don't play much Legacy anymore, but when I did I mainly played UW control type decks (either Miracles or Stoneblade). Both of these decks struggled against Lands, and I've always found Wasteland to be a frustrating card to lose to. I always hoped for a Tsabo's Web that actually could stop Wasteland or Dark Depths, so when I saw this card today I was initially very excited:
But the more I think about it, the less useful it seems to be. It clearly has applications against Ghost Quarter, Valakut, manlands, etc. but the most common thing is hits is... fetchlands. Matt Sperling said it best that fetchlands should never have been printed as is, but that ship has long since sailed. Fetchlands are an integral part to almost every Modern and Legacy manabase, so which decks can realistically play Blood Sun?
You have to want the effect. It's already a fairly narrow affect, especially compared to Blood Moon. Many of the cards Blood Sun is good against can be easily ignored if you are a faster deck than your opponent. Mainly control type decks will be interested in shutting off the uncounterable value lands from the opponent, but these decks are also interested in casting expensive spells, so splashing this off fetchlands just to disrupt won't fit nicely into your game plan. Since splashing this card is off the table, you have to be a deck with lots of red mana. I think red is one of the weaker colors in both Legacy and Modern.
It also doesn't stop some of the more annoying lands in those formats. Tron and Cloudpost still taps for dozens, Cavern of Souls still produces uncounterable mana (if its already in play when you play Blood Sun), and Grove of the Burnwillows still returns Punishing Fire (another bane of control decks in Legacy).
Tsabo's Web is a narrow card, and this is just about as narrow, so while it may seem exciting, and it will definitely see play, it is not a format changing card unless we all agree to stop shuffle with fetches 10x a round. I'm not sure why this wasn't an artifact, with Tsabo's Web already existing and the easier to build two color mana bases without fetchlands. I guess they really wanted to use this very terrible name on a card.
