Does Zenith Blade target a friendly unit?

Ruling: Yes, Zenith Blade targets a friendly unit. Even though the card uses "you may" language, it still targets a friendly unit according to the targeting rules, meaning you cannot play Zenith Blade without a friendly unit on the board.

Nuances:

• The "may" wording does not change the targeting requirement - you still need a valid friendly unit target to play the card, even if you choose not to move it
• This is similar to how Salvage worked before it received errata
• The card targets both an enemy unit and a friendly unit