I have mixed feelings about him. on the one hand, -5 points for +1 wound, +1 attack, +1 rend, more reliable damage, a decent (if not overwhelming) signature spell, a better version of the hunger (very strange since the rule basically works the same on near about everything else, and your choice of either +8 movement OR +1 cast/unbind/dispel OR mortal wounds in place of normal damage is so obviously a steal that future nerfs are inevitable. He isn't even locked to or barred from any subfactions, so he can gain subfaction benefits, most notably casting rerolls & buff aura from Vyrkos or self buffs for slaying units from Kastellai.
So yeah, future nerfs are inevitable, and they could be nuanced (no subfaction benefits, maybe reduced wound, rend, or reach, regular hunger, court of the lost benefits each only once per game, small points increase) or they could be absolutely devastating (massive points increase, stripping out abilities altogether, or even just outright banning him to Legends).
And expecting any nerfs at all to this guy is frustrating, because even pre-nerf I'm not sure of Cado from a purely mechanical perspective. +1 wound alone does not turn a fragile infantry hero into one that can casually wade into melee, especially on a unique hero who can't even benefit from defensive artefacts and command traits, so while his damage output isn't unimpressive, at least when the Spirit of the Fallen is up, you still have to be very careful - maybe too careful - about how and where you engage him. And shooting heavy armies are not going to have much trouble sniping this guy off the board. And he just flat out doesn't have the main reason you field vampire lords these days - the +1 attack command ability. I'm not convinced Cado's personal damage output at all makes up for the 10 to 20 extra grave guard or zombie attacks that a regular vampire lord is contributing instead, especially since the regular vampire lord doesn't have to expose himself to melee to do so. And again, that's before you consider artefacts, command traits, and in Legion of Blood specifically the choice of +2 attacks or +2 to cast that regular Vampire Lords get but this guy won't.
So he's simultaneously obviously overpowered to the point of being almost inevitably doomed to future nerfs yet already has trouble justifying himself next to the generic hero who can't fight nearly as well but more than makes up for that with a defining command ability that this guy just doesn't have.
IMO his best use is probably as a second vampire hero in an infantry heavy Vyrkos army to help spread the buff aura after already taking a regular vampire lord, since the 3e restrictions on command abilities prevent you from using the same ability twice in the same phase anyway. In that role he compares very favorably to little Radukar, the Rat Prince, and the Bat Lady, bringing a bonus to casting key endless spells early on, significant damage output once melee is joined, and an impressive movement speed when needed to get out of dodge or reposition that buff aura as needed. Sort of a half way point between volga (who is a better caster) and big Radukar (who is a better beatstick, although with less rend and fewer mortal wounds if the Fallen is up so I suppose Cado still might win out against especially well armored targets) while being cheaper than both and most of the time gives up less speed when keeping pace with an infantry advance. Still, Volga and Radubeast do exist, and I imagine Vyrkos armies will often pick up one or both of them first and then not have the points spare for Cado.
Maybe I'm underestimating Cado. 4.44 average mortal wound output in combat with the Fallen up before counting buffs from finest moment or command abilities isn't nothing, especially at his modest points value. But I just feel like other heroes are contributing more. If I'm wrong, I hope I have the opportunity to find out first hand before he eats any nerfs. I'll definitely be picking him up right away, but I don't get to play very often, and right now my focus is on other armies.
EDIT: He can't benefit from subfactions, says so right there in his warscroll. Whoops!
That really only reinforces my feeling that he struggles to steal a spot away from a generic vampire lord.
