If you gain a Major Power by non-standard means or from a place other than the Major Power deck, do you have to Forget a card? How about the "gifting" of Entwined Power's threshold or "taking" a Major Power?

If you gain a Major Power by non-standard means or from a place other than the Major Power deck, do you have to Forget a card? How about the "gifting" of Entwined Power's threshold or "taking" a Major Power?

"Gifting" is a transfer and does not require Forgetting, and "taking" explicitly doesn't require Forgetting. But for any Gain of a Major Power, you must Forget unless the effect specifically exempts you.
As usual, you may Forget the Major Power you just gained, if you'd prefer that to losing any of your other Power Cards.