Activate Lancers en-Kor's first ability by paying 0, targeting Daru Spiritualist.
Daru Spiritualist triggers, causing itself to get +0/+2 until end of turn.
Resolve the Lancers en-Kor ability, causing the next one damage dealt to Lancers en-Kor this turn to be dealt to Daru Spiritualist instead.
Repeat an arbitrarily large number of times.
Cast Worthy Cause by paying and sacrificing Daru Spiritualist, causing you to gain life equal to Daru Spiritualist's toughness.
This clever sequence turns a microscopic defensive trick into a towering mountain of life by exploiting the lack of a "once per turn" restriction on Daru Spiritualist. Because Lancers en-Kor features an activation cost of zero, you can endlessly retarget Daru Spiritualist to repeatedly stack its toughness-boosting trigger to astronomical heights. Once your Cleric's toughness is effectively infinite, you seal the deal by casting Worthy Cause, sacrificing the buffed creature to cash in that staggering toughness for an endless reservoir of life.