Does death mana have an use now?
With a cathedral, it can be used to build a Chapel of Death, which then allows Priests of Death, Skeletons, and Ghouls. No clue what those are or how much they cost.
You know, you could fire up admin mode and take a look at some of these things.
Priests of Death, like every tier 3 caster, are pretty potent. They debuff every living enemy on the battlefield, and
permanently debuff anyone they hit - the only permanent debuff in the game, in fact. Plus, you know, good combat stats. Skeletons are kind of interesting. They're only as strong as axemen, but they cost a grand total of zero labor and one money. Ghouls are tougher and somewhat more expensive.
Other tier 3 casters are also pretty sweet. Priests of life buff everyone's defense and resistance, heal, and weaken enemy undead. Air mages buff your archers' range, debuff enemy archers' range, and, starting at level 3, can fly. Hydromancers buff resistance (a
lot) and weaken and slow enemies they hit. Pyromancers are surprisingly team-oriented in their destructiveness; they debuff resistance and buff attack. Earth mages have the strongest magic attack in the game, and buff defense. (Some of these abilities don't kick in until level 3, incidentally.)
I think priests of life and pyromancers are probably the best, but that's just a gut feeling. And there's other fun stuff that mana can get you in the late game, too. Air mana is needed for airships and lightning skiffs, earth mana gets you the only siege unit with better than 1 speed, life mana scores you paladins, fire mana has drakes...