1) Make sure you are a paladin and have 5 points into the Reckoning Talent.
2) Lay on the ground with your back facing the player ( You do not have to do this but it helps to make them crit hit you)
3) Let the player attack you and take some hits and do not attack.
4) Heal your player while he attacks you (Reckoning energy will still build)
5) When he crits you, you will gain extra energy for reckoning.
6) Wait a few then use Reckoning and you should kill them in one hit.
7) You can easily one hit a dual weilding warrior.

THis works best on rogues or fighters since they crit the most.
I put this in exploits as reckoning is going to get nerfed soon because this makes it far to powerfull. Paladins have been complaining how they are nerfed well with this little trick the tables have turned.