Well, it depends.
Personally, I found the battle against the ... first of both enemies much, much longer, exhausting, and difficult. Which was because of the DUPLICATUS spell.
I barely managed to get through it, because I had already 2 members of the party down and had to battle about 4 DUPLICATUS spells - so to say - with the other two.
I found the second part of the battle far easier in some respects.
For insiders of the TDE history, there was quite a huge irony in "battling Answin himself", so to say.
I had expected more and stronger spells by the last of both enemies, considering how devastating the first of both had been to my party.
there were some tricks one could use ... Ointment against burning was good, too. As I told this to someone of dtp or of Radon Lbs, I don't quite remember, at the RPC, he looked surprised that I had used this. Well, to me, it was logical.
I didn't focus my party's development on combat, so this part was very, very diffcult for me - as a hole. Someone at the officil dt forums, who actually called himseld a "R0xx0r", found this last battle and the whole game anyway as "boring". He seemingly put everything into battle and ombat, and I assume he totally ignored any sicial skills. He even admitted that he kind of played games for "levelling" and maxing everything out. He wanted to be the Über-King of everything, so to say. Or so he appeared to me.
With that, general consenus was that Drakensang was simply the wrong game for him. Draknsang is rather a game of athmosphere, of mood, of social interaction (at least for me, and I think I can expect that most of the forum here already knows how I think
)and of ... well, what we rather call "old-school role-playing".
You can find the discussion I talked about here :
http://forum.dtp-entertainment.com/viewtopic.php?f=195&t=15794
All in all, I found he last battle very, very tedious, but not really boring. The devs managed to put enough variation into it to challenge my wits, so to say.