Its better than Sleep, helps get things killed, life totals dropped, and tapping all of the stuff without vigilance (or that couldnt attack for some reason like Dueling Grounds or having defender.) This is a very strong card with a very strong effect, given that all of the creatures out there will swing, leaving their players open for counterswings
Lila, Hospitality Hostess This is an on-curve 3/3 for four Selesnya mana
The other two songs, Seldom All They Seem and One Last Hope, cost less to play, making it less of a drain if you decide to pay ink instead of having your characters sing them
Granted, a big chunk of the fetches opened by individuals will be slotted right into decks, but every Collector Booster box is going to come with 3.3 fetchlands, on average
Youre less likely to come across super-powerful Pokmon V in Prerelease tournaments, so 140 damage is likely to be enough to Knock Out a lot of foes in one hit