>>33087839They're not all malicious, though some are predisposed towards it because of the ways in which they are "born." I tend to avoid the whole "ghost pokemon hatching from egg" business and instead set up a far more complicated system involving a variety of metaphysical interactions and crazy bullshit only possible through the machinations of a deity but it was worth it to make it so that an egg didn't give rise to a fucking spirit.
Ghosts occupy exceptionally complicated roles for most regions - because some can be malicious, some are helpful, some are deceivers and some are just pranksters, they tend to have a negative stigma. This is doubly so in the case of Ghost types that are associated with nastier things, such as Dusknoir.
Ghost type pokemon are also probably in second place for most species to be capable of human speech in a limited to expansive manner. There are a few I marked specifically as not speaking (the Drifloon line, for instance) and some don't ever learn to speak other languages in the first place because they never encounter people, but generally speaking I rather like giving them speech - especially if they can provide alternative perspectives on life and its many quirks (or in their case, unlife, as seen in "Haunted.")
It's a very fun type to work with and the pool is large enough and varied enough that you can pull interesting heroes and villains alike out of it and have them do crazy occult shit under the protection of "because ghosts."