Loyalty to entity?

Does anyone know how to add loyalty to a custom entity? I'm working on a plugin that lets you throw a sword and it comes back like Trident. But I don't have the code for this yet.
Thank you

 

I may be wrong, The LOYALTY enchantment is not implemented in pocketmine, and throwing swords like a trident isn't possible in the clients.
Correct me if I'm wrong

 

true
but this is loyalty to entity

 

Just set motion towards the player?

 

oh, nice idea
also how to make them spinning around you

 

math