How to kill Black Dragons?

Ideally, you need a ring with a large negative resistance – but those are quite rare... Otherwise, phoenixes, mantises (they will entangle and hold them for a long time), ogres (thanks to their strength and offspring), and vampires are good against black dragons. Paladins and barbarians with potions of immortality, and druids with protection spells are also effective. Haven will likely have to rely entirely on illusions from djinns.