[You return before the iron cage once more…]
['Young Sly Ghost' clenches its tiny fists tight, gritting its teeth, its eyes ablaze with the flame of revenge.]
[From its look, it wishes it could break out from the cage instantly, accompany you to the Castle Tower, slaughter the well-known Castle Tower leader, and avenge its grandfather.]
[All you need to do is to destroy this holding cage, then 'Young Sly Ghost' can be freed…]
[Deceptive apostle, you have activated the related conditions.]
['Young Sly Ghost of Origin' wishes to voluntarily become your follower. Will you accept?]
"Oh? A follower."
Lin Xun remembers that Valkyrie was originally a normal summoned puppet.
Using 'Refined Copper Essence' evolved it into a follower. Later on, the Puppet Technician sacrificed himself to give her the 'Refined Copper Heart', which elevated Valkyrie's rank to a growing Watcher.
A follower isn't much different from a standard summon, other than the ability to equip additional gear.