>>535420039
Let's say the opponent has only masquerade on their field, and I used Delaunay to summon Hound, Invader and Jhrelth face down.
Opponent goes into their battle phase and attacks my face down Hound with their Masquerade.
Hound goes straight to the GY without activating its effect.
What makes it so other flip effects work when attacked? For example Desertapir works as expected.