Complex sentence: The only person who does not believe Magua is the Colonial Scout Hawkeye and his Indian companion Uncas whose rough ways, honesty, and vocal common sense has alienated them from the British military command.
Split into simpler sentences: The only person who does not believe Magua is the Colonial Scout Hawkeye and his Indian companion Uncas. Hawkeye's rough ways, honesty, and vocal common sense has alienated them from the British military command.