2011-09-22
If one of Into the Maw of Hell's targets is illegal by the time it resolves, Into the Maw of Hell will still affect the remaining legal target. If both targets are illegal at this time, Into the Maw of Hell won't resolve.
2011-09-22
Into the Maw of Hell targets both the land and the creature. You can only cast it if you can choose a legal target for both.