Once it's on the field, it can destroy both a card you control and a card the opponent controls
It negates your opponents trap card but it doesnt destroy it, merely flipping it facedown before even allowing them to set another trap card from the deck
Miirym, a great Dragon Commander in its own right, lets you copy the dragons that enter the battlefield
Evading them might put them on the back burner for a turn or two, but sometimes that is just kicking the can down the road
Two mana to kill any creature or planeswalker is about the best you could ask for in removal, particularly in this meta
You can cast the exiled card if the token that attacked is still in combat, if it's left combat, if it's left the battlefield, or even if combat is over