If all your creatures are Dragons, five creatures entering the battlefield simultaneously will trigger Dragon Tempest five times for a total of 25 damage
Rona, Herald of Invasion / Rona, Tolarian Obliterator Rona, Herald of Invasion can help you cycle through your deck while also filling your graveyard with resources to reanimate
Maybe you want extra Shift targets for Wide-Eyed Diver and so you will have to play this
If you can play it on turn one, two, or three, it enters untapped, giving you immediate access to mana without slowing your tempo
Not having to print cards for Commander players in every single set means that everything can be a little bit more surgical and precise
The rulebook included here is also a great resource, and is one of the clearest presentations of the rules I've ever seen