Sacrifice 4 Forests (and they have to be untapped to boot) and you get a 4/4 creature for basically mana that lost you four lands
Theres the additional issue that four seems to be the critical mana juncture, so ramping from three to five isnt the best deal, but this also helps four/five color green decks play all the Planeswalkers alongside Centaur Nurturer
Thats the best thing going for it, unfortunately
In Garruk's WakeIn Garruk's Wake (76,145 Inclusions, 4% of 1,911,993 Decks) Now, I just spent a couple paragraphs and another top ten congratulating Ruinous UltimatumRuinous Ultimatum, so you may be shocked to find that I don't actually care for the card that beat it out on this list
haunt effects require creatures to die, which you might not have control over, where forecast effects are limited only by mana