Doubling effects are highly dangerous, because now every pump spell does double damage, and there may even be other things that can double the effect again
Great for Pillow Fort decks or decks which just need to buy some time
Another excellent strategy to run in your blue enchantment removal package is going to steal effects
In metagames where decks like Humans, Affinity, and Spirits are the best decks, I strongly recommend playing only three Dark Confidants
In terms of price, Cavern of Souls goes for around $50 at the low-end of sales, but the card is starting to uptick towards $65 in both versions
Now with predictions of Deaths Shadow, Lantern Control and Izzet Phoenix rising through the Modern ranks, Burn looks primed for resurgence