Hmm that is incredibly true, also she wouldn't be able to see the portals from the exit side. So sneak punches! Then make a kitchen sink land on her, for the giggles.

Edit: Though Reap due to the proximity Krystaal wouldn't have been able to dodge Grimm's attack. Even if she could have seen it coming, though she can have fun with the zombie as Grimm heals.

Edit2: I'm not as creative as you guys think, I'm rather a one trick pony when writing.