Personally, I think it's somewhat biological. That somewhere along the line, monsters may have been introduced to the family tree, but those traits were all recessive, or otherwise not very capable of being expressed before the advent of Duel Monsters-- or otherwise a means of channeling that ability.
"Spirit Sense" on the other hand, is probably similar to that of religious mediums in older times!
Re: [Event]
Huh, Spirit Sense...
Personally, I think it's somewhat biological. That somewhere along the line, monsters may have been introduced to the family tree, but those traits were all recessive, or otherwise not very capable of being expressed before the advent of Duel Monsters-- or otherwise a means of channeling that ability.
"Spirit Sense" on the other hand, is probably similar to that of religious mediums in older times!