those are largely reserved for cards that dont have abilities or effects, or had a little room left over underneath those that did
Derevi, Empyrial Tactician, Hinata, Dawn-Crowned, and Thassa, Deep-Dwelling are a few popular commanders to pair with Willbreaker
Library of Alexandria was the most powerful of all, especially without the modern play or draw rule, allowing players to draw an extra card every time they tapped it
Its good in token strategies that use effects like Doubling Season since it gives them a little resilience to board wipes, and it even works in dragon tribal decks that care about the quantity of their dragons more than their quality
Note that it exiles first, so that means it leaves play and cannot attack unless it has haste
Stop the Opponent Gaining Life Entirely There are black and red cards that prevent players from gaining life, which prevents the lifelink keyword from functioning