Mangara shines the most in multiplayer Commander format, as there is a higher likelihood that one of your many opponents will double spell on their turn
The third ability of Aang's Iceberg allows you to sacrifice Aang's Iceberg as the ability resolves, not as a cost to activate the ability
But more likely than not, you wouldn't, as the surge foil cards that many of you are looking for rarely show up
So shes a niche pick, but seeing Sokka and Kataras grandma waving goodbye with her back to the sunset is a bit comical for what winds up being an uber-useful Magic card
Bloodchief Ascension's first ability checks how much life was lost by each opponent over the course of the entire turn, even if Bloodchief Ascension wasn't on the battlefield the whole time
And if you want to go big, Curaga gives everything you control hexproof and indestructible until the end of turn, plus 6 life