Broken weapons? For example: sword (slashing) versus heavy armor or random. Could be interesting to have a character with various type of weapons.
Having different types of weapons on a character should (hopefully) already give an advantage due to their different skills being suited for different purposes (e.g. axes against shields, clubs for stunning powerful enemies, etc.). This should increase further as we add more weapons that didn’t make it into the demo (like throwing weapons, two-handed axes and warhammers) and their corresponding skills. We then want to make, for example, warhammers better suited against heavily armored opponents by offering an interesting skill that works best against those heavily armored targets, and have swords perform only mediocre or so against them instead of outright break.
Formations? If for example we fight against other mercenaries.
I’m not sure I understand your question correctly; are you asking if the AI will use formations? If so, yes. It already does to a limited extent and will do so more as we add more intelligent enemies, especially of the human variety.
The undead attack “randomly” and only support with archers, but for example could go into several groups: one breaks the shield, other attacks and one defends.
Currently it is only zombies that attack randomly (which I think is pretty in-character given that they’re mindless walking dead), not all the undead. Skeletons, although by no means tactical masterminds, possess more of a cold intelligence and can prioritize targets, split shields if they have a low chance of otherwise hitting their targets, retreat to a defensible position if outnumbered, and such. I suppose the AI should see some improvement in terms of teamwork and specialist roles, though.
Can we get necromancer powers?
No, we want to keep the player side relatively down-to-earth powerwise. There will be some items with magical properties down the road, but they’ll be rare and hard to get. None of them will bestow the power of necromancy because we want to have a certain asymmetry in power between the player and the AI; necromancers (and all non-human enemies, really) should feel special and alien in a way for their unique skills that the player doesn’t have access to.