he's simply called Shadow Knight
not only can he summon a companion of his own, but his companions can summon companions
and after 60 seconds, it's just the shadow knight
that way you can have the power of multiple followers, but you'll also have the bonus of having just one follower come time to travel, not having to trip over so many extra followers
He can be found to the right of Breezehome towards the back
see picture 3
the spell can be found on the table on the great porch in dragons reach
not only can he summon a companion of his own, but his companions can summon companions
and after 60 seconds, it's just the shadow knight
that way you can have the power of multiple followers, but you'll also have the bonus of having just one follower come time to travel, not having to trip over so many extra followers
He can be found to the right of Breezehome towards the back
see picture 3
the spell can be found on the table on the great porch in dragons reach