The activated ability is a single ability that creates two one-shot effects: one that exiles the permanent when the ability resolves, and another that returns the exiled card to the battlefield immediately after In the Trenches leaves the battlefield
Don cards are one of the more compelling elements of the game overall, forcing players to make difficult tactical decisions in the allocation of their limited resources
Madness has been pretty squarely in red and black
That means it can attack or block as soon as it hits the battlefield, but by your next upkeep it'll be turned off again
A mill strategy involves removing your opponents entire deck, usually by putting cards directly from their deck into their graveyard, and plays on a built-in alternate way for the game to end
In addition, I think beginners undervalue the power of permanents, particularly creatures that have the ability to do their thing turn after turn