There are two cards featuring her: Yuna, Hope of Spira which can be found in the Main set, and Yuna, Grand Summoner which can be found in the Commander Deck
It can deal two damage to a creature without any other targets open whereas Red can do that better with Shock at one mana
At the start of each turn, if there is no revealed bounty card, the next one is revealed, and if the bounty deck runs out of cards, shuffle them again and start over
Edric is the preferred choice because it shines by coming down earlier and enabling more colors, though it carries the small multiplayer drawback of also rewarding opponents who attack elsewhere
It might take you a turn or two longer than more mana-efficient decks, but once Ulalek is online and copying your Eldrazi spells, you will be the threat
As far as asymmetrical hatebears go, this is one of the strongest in the Commander format