During fights don't stay just keep moving and remember blocking! Also you can use Daggar to freeze enemies but don't slash them yet! After half of their life is Gone hack n slash him and get the sands you lost back!
When you reach the tomb with the infinite doors near the end of the game the correct sequence of doors is required to be able to progress. Go into landscape view and begin with the door which has the face above it and go clockwise in the following order:
1. 4th door from the entrance
2. 7th door from the entrance
3. 3rd door from the entrance
If you have done it correctly you will be taken to the second level of this room which you navigate the same way. The order now is: