Last night we played our first game with the dark pharoah herald, and the mask monster hit the board. Rather than confront the mask directly, we opted to avoid it for a few turns, and then closed and sealed a gate that had a corresponding symbol to the mask and returned it to the cup.

The herald card indicates that when the mask monster is 'defeated', an effect occurs (the particular effect is escaping me at the moment).

By removing the mask monster through the gate closing, was the monster considered "defeated", thus triggering the effect?

Thanks in advance for the help!

No. "Defeat" is identical to "pass a combat check against." Anything that would have allowed you to take the thing as a trophy (were it not for endless) would count as "defeat."

Dynamite!

Thanks for the fast reply

Yes, especially "Dynamite!"

Tibs said:

Even if I get trophy in encounter? (in graveyard you find corpse…., take from the cup one monster trophy)

Nonimus said:

In case you're instructed to draw a monster & keep it as a trophy, you don't pass a combat check against it. You simply find its corpse. So My Other Faces is not triggered