Probably just had that heal daily on and you got bursted with knights challenge [makes you take double damage from him while daily heals him for a large portion]. I could easily 2 shot people with both dash attacks and knights chchallenge and bad gear.
Main spec i use, slightly altered because Im doing t2 dungeons now : Human cuz i like it but that extra 3 feat points really helps a cleric. At will : astral seal / Blessing of Battle 2 astral seal + 1 BoB = full divinity. this gives small heals from allies attacking and BoB gives like 6% defense and when specced 15% of…