Both sides of the card are viable thanks to the spell denial on your turn, meaning this is one of the few cards that really encourages the transformation aspect of getting it down early for the lower cost, then paying the higher cost to transform it when possible
So well add in Bloodgift DemonBloodgift Demon, Burning-Rune DemonBurning-Rune Demon, Demonlord BelzenlokDemonlord Belzenlok, Kothophed, Soul HoarderKothophed, Soul Hoarder, Rune-Scarred DemonRune-Scarred Demon, and Vilis, Broker of BloodVilis, Broker of Blood
You'll almost certainly just get run over by Gruul Aggro and the board wipes will take you out before you even get a solid footing
Double Trouble (SPE) $37 Double Trouble is a one-shot Unnatural Growth thats an instant and is easier to cast
So I play Booster Tutor