Yeah, this card's pretty bad m'kay? At least, outside of block it's pretty bad. 5 mana to deal 7 damage is pretty good, but 5 mana for 4 damage isn't that great and the potential to deal 0 damage for 5 mana is just terrible. Outside of a Lorwyn block tournament, this is just not usable (unless you REALLY need that extra Elemental spell in a tribal deck). There's enough cards out there that can change creature type on the fly that can negate this. Also, it's at sorcery speed. There aren't that many good sorcery speed burn spells that are worth it (Flame Wave and Brightflame being examples of good sorcery speed burn spells).