Furthermore, the combination of flying, first strike, and lifelink make this the perfect creature to stave off aggressive decks
Etali is unfortunately fairly vulnerable for a big dinosaur, and a kill-on-sight card in Commander, so you'll also want to have cards that provide Etali with haste, so it will at least have a chance to attack
K'rrik, Son of Yawgmoth K'rrik, Son of Yawgmoth breaks black spells by turning mana costs into life payments
the next card is better but needs those colors but that's it
Its a bit slow, but it shines when you need to hit land drops, fix colors, or deplete your deck of lands to maximize exile effects like Wrenn's Resolve and never run into dead cards
Vivi isn't the only culprit, either, as Proft's Eidetic Memory was controversial, too