I am already planning to try Vivi out in my Izzet prowess deck, which will either pop off, or get removed on sight
A nice thing about this commander is that its ability works whenever you attack with any creature, so its ready to go as early as turn 4-5
Wildcards are MTGA's way of making sure that you can still collect the cards that you need
Decimate can either wreck a single player's board or hit different permanents among multiple opponents as needed, such as saving the artifact removal part for an artifact-heavy deck
The biggest difference is that Rayami wants those cards to die on the battlefield, so sacrifice outlets are important, whereas Indominus Rex wants those cards in your hand, which it can then easily refill with its own ability
Whenever you roll a 2, each opponent loses 1 life and you gain 1 life