Can Sett, The Boss use his replacement effect to protect a unit that is already in base (e.g., when targeted by Harnessed Dragon)?

Ruling: Yes, Sett can use the replacement effect to protect a unit already in base. You do as much of the effect as possible, and being recalled is not a requirement to use the protection.

Nuances:

• The replacement effect works even when the recall portion cannot be performed
• Effects are resolved as much as possible even when some parts cannot be completed