The reaper general has cool graphics but otherwise, he/she doesn't differ from BHG, so not really worth buying for those who already have multiple fast generals.
So we thought that he/she could have a cool special ability, like in a certain other game, he/she could raise a small percentage of the enemy units killed in a battle as zombies who help in the fight - perhaps zombies'd have the same (or lower) statistics as recruits, would appear in the next round and only live for the duration of that same battle, or they would appear after a fight is won and only last for the next attack, whatever. Just make him special! Maybe even retroactively.