There are a couple of evil enhancements I've wanted to create, and this is one of them (the other is in a coming soon post). They are based off of pagan/occult practices that God warned Israel not to participate in from Leviticus 19 since the Canaanites that they were going to displace were practicing, which is why the land was defiled and why God was using Israel to bring judgment on them.
One of those practices was cutting themselves as a mourning ritual for the dead. I made this EE to be black so as to be representative of Canaanites' practice of this ritual, and pale green due to the ritualistic, occult spirit involving this practice. The ability's nexus is based off of deceased humans, which is representative of evil humans in all discard piles. Based upon this number, certain costs and benefits happen: decrease of your evil humans (symbolized by the cutting of one's self), number of heroes withdrawn (heroes being taken-aback and backing off from this practice), and the CBI portion being conditional based upon the number of discarded evil humans.
Only an evil human can use this ability, which would directly affect the blocker by decreasing his/her toughness, potentially having the defender taking a chance in discarding his blocker(s) if their toughness isn't high enough. It's also thematic since these are evil humans who are specifically doing this practice, not some demon or symbolic character. It also has the cost-benefit of withdrawing several banded heroes but possibly causing some of your evil humans in territory and/or battle to be discarded based upon the decrease (which is only a temporary decrease).
The benefit is an ITB that can conditionally withdraw several heroes and can be a CBI battle-winner depending on how many evil humans are in the discard piles. This card would be most effective when played toward the middle or end of the game. In addition to the costs mentioned above another cost/down-side to the defender is that it can be prevented by heroes or by other ECs.
I hope you enjoy this card. Any positive, constructive feedback is always welcome!