Some are great commanders for a merfolk deck, while others have unique abilities that lead to different types of builds
The second ability is pretty interesting if youre being particularly sneaky and only have a single artifact in your deck since you can guarantee youll get that card
Brackets 4 and 5 are focused on a higher power or even a competitive experience
They are random, not-that-expensive, and very reprintable Modern and Standard cards
Its extremely elegant if you get stuck on mana and cant cast stuff, youre likely going to fall behind on board and get hit, which means more people will guess your cards, which means youre more likely to get Treasures, which then fixes your colors and catches you up
Nowadays MTG uses the term noncreature spell more often