What makes someone a good Devil Host?

In the recent chapter (ch. 385), Adrammelech says that Yami has become perfect for devil possession ever since he was sacrificed to open the gates to the Underworld.

Lucius claimed he had the greatest potential to be a devil-host in his family's history.

We have seen characters like Asta, Nacht, Julius/Lucius, the Dark Triad and now Yami being devil hosts.

So what makes someone a good devil host? Why wasn't someone like Yami considered good for devil possession before his capture? Or, what exactly makes Lucius the best devil host?