First off, no matter what they claim or what their reputation is, they're still human. They are not perfect nor are they all powerful. A side note to that for this particular place is that he does not have any access to abilities he had back in your home.

Secondly, there will always be an advantage, you just have to look for it.

Thirdly, never be afraid to ask for support or allies. Friends in any place can turn the tides of war. However, always keep in mind that this usually comes with a price and you must know what you are willing to give.