As the Cleric Defiler wiki entry says "All slotted Negative and Death spells have a % refund chance". The suggestion is, add the new spells with the [Negative] and [Death] descriptors.
Spells that come to mind are:
Dehydrate
False Life
Greater Life Transference
Life Transference
Negative Energy Flood
Spinal Tap
Stop Heart
Withering Ray