"Typecasting" by Mark L. Gottlieb
"The thing about puzzles is that they're tricky. Sometimes they get so complex that I even fool myself. As I create a Magic puzzle, I go through many versions trying to find a setup that works. Unfortunately, when I submitted Tuesday's puzzle, Martin's life total was left uncorrected from an earlier draft. He should start at 21 life, not 23. Sorry about the mix-up, and I hope you'll give the puzzle another shot."
There's just enough time for one more Onslaught puzzle before Legions kicks in. You're playing New Jersey Devils goalie Martin Brodeur using all-Onslaught decks. Martin played an Imagecrafter on his turn and attacked with some of his creatures. It looks like he'll overwhelm you next turn, but it's time for your type-changing trickery to finally pay off. It's the beginning of your first main phase. Even though Martin is at 21 life, you can defeat him this turn. How?