Packbeast is only good when you wind up with a focused deck, while the removal spells (like the various Exhales) are good no matter what your deck looks like
I'll go into the details of what appears on the card in a second, but first let's see what they look like: Card Number and Set : This very important, because we have a lot of cards in motion at any given time and names are liable to change
It has the combat trick, it has the removal spell, and then it also has: Stretcher B or G Instant If a card named Goblin Chainwhirler has entered the battlefield this turn, destroy all creatures your opponents control
New Way Forward looks very potent in Commander
A shift ability lets this combo nicely with Fairy Godmother: Here to Help
They also won't trigger if a card on the battlefield transforms into a legendary land, as the Ixalan and Rivals of Ixalan double-faced cards do