Is it possible for a witch to have a familiar who is a person of a different aspect, but has a lot of connections to the witches aspect? (Sorry if that sounds confusing)

It is very likely we’ve actually seen this in action already, with Folykl, a possible Witch of Void, using Kuprum as her Familiar, specially with the comparison made that she’s using him as her ‘steed’, giving an actually solid Void connection.