I was fighting the liches north of the heart today.
Typically, I'd pull one away from the group, fight it to half health, fall back to cure or heal, then go back to finish it off. I was rolling through them. Killed about a dozen and only quit because my pack was full. I hit single digits in health once and only failed healing a handful of times.
My healing and magic resistance are apparently vastly improved since the last time I tried to fight liches.