Can Yasuo's leader skill move a unit from base to battlefield, from battlefield to base, or both?

Ruling: Yasuo's leader skill allows you to move a unit either from base to battlefield OR from battlefield to base. You choose one of these two options.

Nuances:

• This ability is activated during your turn and cannot be used as a reaction to spells or abilities
• If a unit is moved to base or hand by some other effect, targeted spells like Rebuke that affect units on the battlefield would resolve to no effect (though they don't "fizzle" - they still resolve for purposes of abilities that care about resolution)