If I take control of an enemy unit with Hostile Takeover (played from hidden during a showdown) and then use Portal Rescue on that unit, do I still return it to the original owner at the end of my turn, or does the Portal Rescue effect override the return?

Ruling: When a unit leaves the board (like getting banished by Portal Rescue), all effects on it are removed and it's considered a different unit. The owner (original player) plays the card from their banish pile, so they get back control. Since you can't lose control of a unit that's no longer on the board, it won't recall to base.

Sequence:

• Hostile Takeover takes control of enemy unit until end of turn
• Portal Rescue banishes the unit
• All effects (including Hostile Takeover's control effect) are removed when unit leaves board
• Owner plays the card from banish, regaining control
• Unit does not return to your opponent's base because the control effect was already removed

Nuances:

• When you control a unit and it dies, you trigger "friendly unit dies" effects and draw from effects like Hidden Blade
• The opponent cannot use cards like Zhonya's to save the unit because it's not friendly to them while you control it