This is a good card, but one that requires being used in a specially-prepared deck - preferably a deck loaded with sorcery and instant cards for dealing damage, as opposed to lots of creatures
Legality depends on the tournament format -- Cold Snap can be legal in some formats and banned or restricted in others
On one hand, corrupted cards are a clear signal of a poison strategy, but it still makes me anxious to see across the table
If it's a land card, you may put it onto the battlefield
Everyone who wantsa be someone's carrying a torch for that gal, lit bright as day
But even without those tricks, its pretty easy to cast: A deck with fetch lands and some cheap cantrips has no trouble getting this into play quickly and overwhelming the board with an army of manifests