what is the best strategy?
There is no ‘best’ strategy. If even there was, the point of the discourse is not to tell others how to complete something, but just hint them. So, sorry, but we can’t answer your question. We can only help when you your code is not working or you don’t have any clue how to pass a level.
ok (strategys later)
best stregy is to use a fast warrior hero that has lots of hp (eg arryn). and spam click flags to dodge attacks