Here are afew simple suggestions to improve defilers.

1. Make the 'Fast Lob' trait reduce the induction of all healing skills with 1 sec.

Fell restoration is the only defiler heal that can counter the direct damage that freeps lash out. It has a 2.5 sec induction and those 2.5 seconds are worth alot of health in todays ettens. In addition, if you by any chanse, would have Addle on (which in most cases adds another 75% induc time) it would take close to 5 sec to get that one heal off.
Remember, Fell Restoration has a 30 sec cd so it's nothing you can spam all the time.

2. Increase the damage dealt from blood of fire.

By how much I havn't figured out yet. from 50 to 100 would be a good change or even 150.

This skills does no significant change to the enemies health bars as it is at the moment and combined with the low dps we have its not likely that it will affect the attacker enough to scare them off. Compare this to the warden reflect skills, which on the other hand have a duration, they relfect up to 250 on any common fire and shadow damage if stacked 2 times.
I only want Blood of fire to make change in combat.

These are just two things i thought turbine could've thought of from the start.

Feel free to leave your opinions.