When getting a +1 from empowering a unit, is it acted like a buff or is it only for that turn?

It's neither a buff counter nor a "this turn only" effect. The +1 Might from an [Empowered][>] ability (e.g. on Punching Poro, Akali, or Apprentice Mage) is a continuous passive effect that lasts as long as the unit remains empowered.

• Not a Buff — no counter is placed, so it doesn't interact with the "one buff per unit" rule (Rule 702.3). It also doesn't conflict with or stack as a Buff would.
• Not temporary — the Empowered status "lasts indefinitely until the card leaves the board or is disempowered" (Vendetta rules, Patch Notes 2026-07-17). So the +1 persists turn after turn.
• Conditional — if the unit is disempowered or leaves play, the [Empowered][>] ability becomes inactive and the +1 is lost.

In short: the +1 stays as long as the unit stays empowered — no timer, no buff counter, just a continuous bonus that turns on and off with the Empowered status.