Well, Land Grant effectively made it fourteen, which was still low, but now high enough to think youll consistently get at least one
The single most important thing about winning and playing Magic is having a good mana base
Its still immune to most board wipes and single-target removal
That means you cant pay other alternative costs on that card if you cast the plotted card from exile
Finally, the ultimate isn't even good all the timeif you are winning and have a decent board, you might want to keep your own permanents rather than take your opponent's, especially since Aminatou, the Fateshifter is more about synergy than raw power, so your cards will likely be more valuable to your deck than your opponent's cards
Whenever Rottenmouth Viper enters or attacks, put a blight counter on it