Ghoul assassination unit lead by a combat-tuned Vamp with Nightshroud. Get that Vamp (or another) the power where you get a march move with Ghouls and just get there as fast as possible and chop him up into tiny bits with a well-positioned charge. Make sure to have a Ghast to soak up the champ trying to challenge to draw away your Vamp.
Alternately you can kind of mess up Teclis if he sits in the back by using Nightshroud and Lycni on a combat Vamp with the Scout power. The big difference here being that you have to take a support unit that can get to your Vamp quickly to assist. The nice thing about this is if the unit Teclis is in isn't too huge, you might be able to challenge and overkill the HElf character(s) that are not Teclis by enough to not die to combat resolution, limiting what Teclis can cast and allowing your other stuff to get stuck in with fewer problems.
A baby seal walked into a club.