Q
When High alert
leaves set zone C other than by its own effect, is it put in the abyss?
A
Yes. If you replace it with another area enchant card yourself, or it's affected by your opponent's card's effect, it's put in the abyss.
The card itself has no SEND TO POWER, but it's put in the power charger when "Your opponent reveals the top card of their deck at the start of the turn, and a card with a power cost of 6 or more is revealed from their deck".