It sounds like you are talking about the end of D2:ED, not DKS (also, I think you may have intended this to go in an English forum, rather than German).
For the final battle in the Hall of Echoes, there are a few strategies and techniques that could have helped (see
I need help with a battle (Spoilers)).
The Dragon Knight Saga includes a remastered version of D2:ED together with the add-on Flames of Vengeance. On the PC, FoV picks up immediately after the end of D2:ED, with a seamless transition into the add-on from the original game. Unfortunately, FoV is too large to be released as DLC on the Xbox, and Larian could not get just the add-on published, so the only way to get it is with DKS (North American release April 12th -
The early dragon gets the art!).
There were too many changes made in the remastered version to maintain save game compatibility with D2:ED, but with DKS you can start a new level 35 character at the beginning of the FoV section, if you don't want to replay from the beginning.
Welcome to the forum.