Not quite sure what you're after here. It's a slightly odd scenario. I mean, War Maiden/Deadly is about as templar specific a build as you can get. Dks have hardly any magic damage, magsorcs aren't going to benefit much from deadly.

You asked about templars vs DKs the other day. If you're trying to make up your mind and want someone to say templars are best, trust me, you don't need a scenario to do that.

For dueling?

Honestly whichever one pumps out the most unpurgeable damage will make the most use of it. I use it on my vampire MagDK to make Blood for Blood free, but that's the only reason I'm running it in all honesty. Group fights I'm going Death Dealer's Fete instead and using BfB sparringly unless I can get away with it.