Someone mentioned dust. Seeing the dust turn any creatures that have contact with it into hideous beasts would be sweet.
This will technically be doable in the next version won't it ? Induce a werewolf-y syndrome that is triggered at all times and make the dust induce that syndrome.
Antymatter, while some of your ideas are in fact good, you really need to put more thought into them. What kind of curses? What do you mean by "Megabeast"? How bad is 'really bad'?
This suggestion seems incomplete, you really can't expect us to fill in the blanks for your suggestion.
This is a super empowered elf. Bad luck follows him. He has the power to go through walls. He wants your cats and booze!
Again, it is very synthetic and would be good if you would care to elaborate more. But it IS a wonderful idea ! New randomized attributes for megabeasts, or forgotten beasts.
Technically, I guess we could mod in curses that turn people into megabeasts, making them prone to attack no ? A bad luck syndrome is coming in too.
Also, new abilities, strengths and weaknesses. Weaknesses and immunities are going in next time, but only to certain materials... Could we add other methods of protection or weaknesses ? Like a monster that can't cross running water, or another that can only harm someone if that person is wearing some specific equipment ? The ability to destroy building and constructions made of a certain materials ?
Or the ability to run any object near it from a specific type into another, or any material into another ? By distance or by touching it ? Altering the materials property around, such as making the melting point of everything lower, so your dwarves' iron armor boil on your soldiers !
It also highlights something : in fortress mode, megabeasts attack sometimes, but they have no goal. They just come to slaughter you. In Worldgen, they come and snatch things and then go away. Having them appear on the map, stating what they want would also give you the possibility to acknowledge that you are fucked, to pay tribute and just sacrifice all your booze to a dragon so it will go away.
Also, do night creatures ever snatch someone in fortress mode ? I've never had that. If it's not it, it really should ! They'd come as an ambush, snatch someone who'd just silently disappear from the list in the same way kidnapping works.