Firstly, I never noticed that Leech heals the attacker whenever it causes extra damage - my bad!
But the question is, how does Leech work when applied to monsters (who don't have fatigue at all)?
Leech (WoD pg 6)
For every wound token lost due to a Leech attack, the target also loses 1 fatigue (or suffers 1 additional wound, ignoring armor, if the target is
out of fatigue
) and the attacker is healed of 1 wound
Can you be 'out of' something that you don't even have a stat for? Possibly, possibly not...
If not, does the attacker heal if the extra wounds aren't caused?
The question comes up due to the new Trickster skill - and also the Count's upgrade for Razorwings that gives them all Leech and Ironskin (therefore it becomes a possibility for Necromancy as well).
There may be other new potential interactions too with more opportunities for monsters to be hitting other monsters that weren't previously possible....